Epidemiology of pertussis in Casablanca (Morocco): contribution of conventional and molecular diagnosis tools

Pertussis outbreak in children hospitalized in Rabat (Morocco)

INTRODUCTION

Cyclical pertussis epidemics primarily affect young infants. This study aims to estimate pertussis prevalence during the ongoing 2023 outbreak at our institution, focusing on affected age groups and clinical presentations.

MATERIEL AND METHODS

This retrospective study includes patients admitted to Rabat University Hospital Center from 1st January 2021 to 30th June 2023. Symptomatic patients underwent Multiplex Respiratory Panel PCR testing for respiratory infections. The analysis included cases where RT-PCR identified Bordetella spp., with data analysed using SPSS 15.0.

RESULTS

Pertussis cases sharply increased from December 2022, constituting 85.4 % of positive samples. Most cases (78.2 %) occurred in infants under 3 months, presenting symptoms such as coughing (94.5 %) and dyspnoea (94.5 %). Pertussis was suspected in 60 % of RT-PCR confirmed cases. B. pertussis DNA was identified in 81.8 % of cases and B. parapertussis DNA in 18.2 % of cases.

CONCLUSION

The study exposes a significant pertussis outbreak affecting predominantly young infants.

Bordetella holmesii: Causative agent of pertussis

Bordetella holmesii is a bacterium recently recognized in 1995. It is a gram-negative coccobacillus that can cause pertussis-like symptoms in humans as well as invasive infections. It is often confused with Bordetella pertussis because routine diagnostic tests for whooping cough are not species-specific. The prevalence of B. holmesii as a cause of pertussis has increased in several countries. Therefore, B. holmesii assays are important for determining the epidemiology of pertussis, for the choice of an effective treatment, and for detecting vaccination failures.

[Pertussis worldwide. Vaccinating children and adults]

Pertussis (whooping cough) is an important cause of morbidity and mortality in infants world-wide, and continues to be a public health concern despite high vaccination coverage. The disease, caused by bacterium Bordetella pertussis, is present in all countries. Before vaccines became widely available in the 1950s, pertussis was one of the most common childhood diseases worldwide. According to WHO, estimation of deaths was 4 millions/year in 1950 and 100 000/year in 2015. But morbidity remains important with a high circulation of the bacterium determining atypical clinical forms after whole cell or acellular vaccines use. This is due mainly to the absence of booster doses in adolescents and adults. Major progress are generalisation of PCR and vaccination of mother during pregnancy. A resurgence of pertussis is observed after generalisation of acellular vaccines use. In China the progression of allele ptxPl was found in all areas following the use of acellular vaccine. This allele, rare before acellullar vaccine, is linked to a macrolide resistance, and reaches more than 30% of strains isolated in hospitalised children.These evolutions must be evaluated in clinical forms and genotyping of all strains, in all areas.

[Epidemiological profile of pertussis in infants in Casablanca from 2012 to 2019]

Pertussis is a real public health problem due to high neonatal morbidity rates and resurgence despite high vaccination coverage. The purpose of this study is to analyze the epidemiological profile of pertussis in infants hospitalized from 2012 to 2019. We conducted a retrospective, descriptive study over a 7-year and 8-month period from January 2012 to July 2019. It involved 500 infants admitted with clinical suspicion of pertussis. The average age of infants was 72 days, ranging from 28 days to 18 months; 75% of infants were less than 3 months old. The peak incidence was registered in 2012 and 2016, with a summer predominance (32%); 460 infants (92%) were not or incompletely vaccinated, 42.2% of whom were too young to be vaccinated. A probable contaminant in the entourage was found in 43,6% of cases. Whooping cough and cyanosis were the main reason for hospitalization (77.6%). Chest radiography objectified bronchial disease (25,4%) and alveolar foci (22.7%). Blood count performed in 410 infants showed hyperlymphocytosis in 67.5% of cases. Polymerase chain reaction (PCR) on nasopharyngeal sample collected from 206 infants was positive for Bordetella pertussis in 64% of cases; 118 PCR performed in mothers were positive in 47.7% of cases. All infants received Clarithromycin. Pertussis is a major cause of morbidity in infants in Casablanca. The prevention strategy is based on vaccination of family members of infants. However, vaccination of pregnant women appears to be more effective.

Safety and Clinical Benefits of Adacel® and Adacel®-Polio Vaccination in Pregnancy: A Structured Literature Review

Vaccination in pregnancy using a tetanus toxoid, reduced dose diphtheria toxoid, and reduced dose acellular pertussis (Tdap) vaccine is important for prevention of severe pertussis disease in young infants. The objectives of this systematic literature review were to search for original research studies evaluating the vaccine effectiveness, immunogenicity, and safety of Adacel®/Adacel-Polio® used during pregnancy to prevent pertussis disease in young infants. Medical databases used included EMBASE, BIOSIS Previews, and Chemical Abstracts, with search terms related to pregnancy, vaccines/immunization, safety, pertussis, effectiveness/efficacy, and immune response; other potentially eligible reports were included where applicable. Search results were restricted to literature published from 1 January 1995 to 26 July 2021. A total of 2021 articles and 4 other reports were identified for primary review. A total of 49 publications qualified for inclusion after primary and secondary reviews. Effectiveness studies of Adacel or Adacel-Polio given in pregnancy consistently showed high levels of protection from pertussis disease in the newborn (vaccine effectiveness: 91-93%). In immunogenicity studies, the response in pregnant women was consistent with that of non-pregnant women. Infants of mothers vaccinated with Adacel or Adacel-Polio in pregnancy had higher anti-pertussis antibody levels at birth and at 2 months of age compared to infants born to women vaccinated with comparator vaccines, placebo, or those not vaccinated during pregnancy. There was evidence of a slightly decreased response to primary pertussis vaccination in infants of mothers vaccinated with Adacel or Adacel-Polio, but this was not thought to be clinically significant. In safety studies, Adacel or Adacel-Polio vaccination was well tolerated by pregnant woman and not associated with pregnancy, postpartum, or neonatal complications. In conclusion, Adacel or Adacel-Polio vaccination in pregnancy is highly effective in protecting young infants from pertussis disease, with a favorable safety profile for both pregnant women and their infants.

Clinical evaluation of a new rapid immunochromatographic test for detection of Bordetella pertussis antigen

A more rapid and less complicated test to diagnose pertussis is required in clinical settings. We need to detect Bordetella pertussis, which mainly causes pertussis, as early as possible, because pertussis is more likely to become severe in infants, and people around them can easily become a source of infection due to its strong infectivity. Nevertheless, methods that can detect B. pertussis rapidly and efficiently are lacking. Therefore, we developed a new immunochromatographic antigen kit (ICkit) for the early diagnosis of pertussis. The ICkit detects B. pertussis antigens in a nasopharyngeal swab without equipment and provides the result in about 15 min with a simple procedure. Additionally, a prospective study to evaluate the ICkit was conducted in 11 medical institutions, involving 195 cases with suspected pertussis. Compared with the real-time polymerase chain reaction (rPCR), the sensitivity and specificity of the ICkit were 86.4% (19/22) and 97.1% (168/173), respectively. The ICkit detected the antigen in both children and adults. Furthermore, the ICkit detected the antigen until the 25th day from the onset of cough, when rPCR detected the antigen. Thus, the ICkit demonstrated a high correlation with rPCR and would help diagnose pertussis more rapidly and efficiently.

Hospital-based prospective study of pertussis in infants and close contacts in Tehran, Iran

Background

Pertussis remain a global health concern, especially in infants too young to initiate their vaccination. Effective vaccination and high coverage limit the circulation of the pathogen, yet duration of protection is limited and boosters are recommended during a lifetime. In Iran, boosters are given at 18 months and 6 years old using whole pertussis vaccines for which efficacy is not known, and pertussis surveillance is scant with only sporadic biological diagnosis. Burden of pertussis is not well understood and local data are needed.

Methods

Hospital-based prospective study implementing molecular laboratory testing in infants aged ≤6 months and presenting ≥5 days of cough associated to one pertussis-like symptom in Tehran. Household and non-household contact cases of positive infants were evaluated by comprehensive pertussis diagnosis (molecular testing and serology) regardless of clinical signs. Clinical evaluation and source of infection were described.

Results

A total of 247 infants and 130 contact cases were enrolled. Pertussis diagnosis result was obtained for 199 infants and 104 contact cases. Infant population was mostly < 3 months old (79.9%; 157/199) and unvaccinated (62.3%; 124/199), 20.1% (40/199) of them were confirmed having B. pertussis infection. Greater cough duration and lymphocyte counts were the only symptoms associated to positivity. Half of the contact cases (51.0%; 53/104) had a B. pertussis infection, median age was 31 years old. A proportion of 28.3% (15/53) positive contacts did not report any symptom. However, 67.9% (36/53) and 3.8% (2/53) of them reported cough at inclusion or during the study, including 20.8% (11/53) who started coughing ≥7 days before infant cough onset. Overall, only five samples were successfully cultured.

Conclusion

These data evidenced the significant prevalence of pertussis infection among paucy or poorly symptomatic contacts of infants with pertussis infection. Widespread usage of molecular testing should be implemented to identify B. pertussis infections.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06266-6.

Bordetella pertussis in School-Age Children, Adolescents, and Adults: A Systematic Review of Epidemiology, Burden, and Mortality in Africa

The Global Pertussis Initiative recommends diphtheria–tetanus–pertussis (DTP3) vaccination of infants aged < 1 year for all African countries, and recommends the vaccination of pregnant women as a primary prevention strategy. However, the role of older children and adults in the transmission of pertussis in Africa is not clear. A systematic search of MEDLINE, EMBASE, and BIOSIS was undertaken to identify studies published between 1 January 1990 and 17 June 2019, with information on pertussis epidemiology, burden of illness, and mortality in school-aged children, adolescents, and adults in Africa. Studies identified for inclusion were reviewed narratively because a statistical comparison was not possible because of the mix of methodologies used.

Studies from North Africa (Morocco, Tunisia, and Algeria) reported that although DTP4 vaccine coverage is high, severe pertussis-related complications persist in young children, vaccine-acquired immunity wanes in adolescents, and household contacts are important transmitters of infection. A serosurvey in Gambia showed that 6% of the general population had pertussis antibody levels suggesting recent infection, and studies from Senegal showed that pertussis infection was endemic despite high DTP3 coverage. During a pertussis outbreak in Ethiopia, the case fatality rate was 3.7% overall, and 6.3% among children aged 5–9 years. In a case-surveillance study in South Africa, the incidence of pertussis among hospitalized children was 526/100,000, and infection rates were higher in HIV-exposed and -infected children compared with uninfected children. In conclusion, the highest burden of pertussis in Africa is among infants, and surveillance is lacking in many African countries meaning that the burden of pertussis among infants and infection rates among older children and adults are not well reported, and likely underestimated.

Pertussis among patients with clinically compatible illness in the Amhara Regional State, Ethiopia

BACKGROUND

Pertussis is an acute respiratory tract disease caused by Bordetella pertussis. In 2014, 24.1 million pertussis cases, resulting in 160,700 deaths, were estimated to have occurred worldwide. This study aimed to determine the epidemiology of pertussis among patients with clinically compatible illness who visited selected hospitals in the Amhara Regional State of Ethiopia.

METHODS

A cross-sectional study design was used to review pertussis patients with clinically compatible illness. Nasopharyngeal swabs were collected from 515 patients from July 2018 through February 2019. DNA was extracted from all nasopharyngeal swabs and samples were analyzed using real-time (RT-) PCR. Crude and adjusted odds ratios with corresponding 95% confidence intervals were estimated using bivariable and multivariable logistic regression analysis, respectively.

RESULTS

The overall prevalence of Bordetella species among the study participants was 156 of 515 (30.3%) [95% CI = 26.4-34.6] as determined by Bordetella RT-PCR, including: 65 (41.7%) B. pertussis, 89 (57.1%) indeterminate B. pertussis, one (0.6%) Bordetella holmesii and one (0.6%) Bordetella parapertussis.

CONCLUSIONS

This study found that pertussis is potentially endemic and a common health problem among patients visiting health institutions in the Amhara Regional State of Ethiopia. More data regarding pertussis in Ethiopia could inform development of effective prevention strategies.

PCR-based diagnosis of whooping cough in the Russian Federation

The aim was to determine how often the PCR method is used in different laboratories in Russia. In 2018, we conducted a questionnaire survey in diagnostic laboratories of medical organizations and the Centers of Hygiene and Epidemiology that performed PCR studies to identify microorganisms of the genus Bordetella in all 85 Russian regions. We found that in 2013 the PCR was used in 33 (38.8%) regions, but in 2017 the number of regions increased to 64 (75.3%). During 2013-2017 the study has not been applied in 21 regions. The number of PCR tests performed in the laboratories of medical organizations was significantly different. There has been an increase in the number of tests for the diagnosis of pertussis among people with clinical signs of infection and among contact persons in foci of infection. Compared to the Centers of Hygiene and Epidemiology, in medical organizations the rate of introduction of the PCR was higher. Between 2013 and 2017 the proportion of samples containing DNA B.pertussis decreased, but the proportion of samples containing DNA of other representatives of the genus Bordetella increased. Moreover, in the case of isolation DNA Bordetella spp. clinicians diagnose «Whooping cough, other unspecified organism», since there is no information on the species of the pathogen. Thus, in order to improve the diagnosis of pertussis, it is necessary to optimize PCR tests by including target genes that allow to identify of currently relevant DNAs of different representatives of the genus Bordetella.

Bordetella pertussis, a reemerging pathogen in pediatric respiratory infections. A study in Quito, Ecuador

Bordetella pertussis is the causative agent of pertussis, which mainly affects unvaccinated children, while Bordetella parapertussis causes a disease presenting clinical characteristics that are indistinguishable from whooping cough. Despite high vaccination coverage, pertussis remains a public health concern worldwide, with approximately 140000 cases reported annually. Here we determined the prevalence of B. pertussis and B. parapertussis infection among infants under one year of age by polymerase chain reaction (PCR); our aim being to identify whether the data obtained relates to the relevant sociodemographic and clinical data. The study included 86 samples of nasopharyngeal swabs from infants aged between 0-12 months, who were reported as probable cases of whooping cough by the health centers around the Ecuadorian highlands, from August 2016 to July 2017. The nasopharyngeal swabs were cultured and microbiological and molecular analyses were performed. B. pertussis was identified by PCR in 41% of the samples (30/86), more than half of which corresponded to infants aged between 0-3 months. Moreover, a statistically significant correlation (p<0.05) between the identification of bacteria in culture and the catarrhal stage of the disease was observed. The results obtained from the study highlighted the need for an active national surveillance of pertussis, in particular for laboratory testing, to provide a highly sensitive and more specific diagnosis of Bordetella infection.

The burden of laboratory-confirmed pertussis in low- and middle-income countries since the inception of the Expanded Programme on Immunisation (EPI) in 1974: a systematic review and meta-analysis

BACKGROUND

An effective vaccine against Bordetella pertussis was introduced into the Expanded Programme on Immunisation (EPI) by WHO in 1974, leading to a substantial global reduction in pertussis morbidity and mortality. In low- and middle-income countries (LMICs), however, the epidemiology of pertussis remains largely unknown. This impacts negatively on pertussis control strategies in these countries. This study aimed to systematically and comprehensively review published literature on the burden of laboratory-confirmed pertussis in LMICs over the 45 years of EPI.

METHODS

Electronic databases were searched for relevant literature (1974 to December 2018) using common and MeSH terms for pertussis. Studies using PCR, culture or paired serology to confirm Bordetella pertussis and parapertussis in symptomatic individuals were included if they had clearly defined numerators and denominators to determine prevalence and mortality rates.

RESULTS

Eighty-two studies (49,167 participants) made the inclusion criteria. All six WHO regions were represented with most of the studies published after 2010 and involving mainly upper middle-income countries (n = 63; 77%). PCR was the main diagnostic test after the year 2000. The overall median point prevalence of PCR-confirmed Bordetella pertussis was 11% (interquartile range (IQR), 5-27%), while culture-confirmed was 3% (IQR 1-9%) and paired serology a median of 17% (IQR 3-23%) over the period. On average, culture underestimated prevalence by 85% (RR = 0.15, 95% CI, 0.10-0.22) compared to PCR in the same studies. Risk of pertussis increased with HIV exposure [RR, 1.4 (95% CI, 1.0-2.0)] and infection [RR, 2.4 (95% CI, 1.1-5.1)]. HIV infection and exposure were also related to higher pertussis incidences, higher rates of hospitalisation and pertussis-related deaths. Pertussis mortality and case fatality rates were 0.8% (95% CI, 0.4-1.4%) and 6.5% (95% CI, 4.0-9.5%), respectively. Most deaths occurred in infants less than 6 months of age.

CONCLUSIONS

Despite the widespread use of pertussis vaccines, the prevalence of pertussis remains high in LMIC over the last three decades. There is a need to increase access to PCR-based diagnostic confirmation in order to improve surveillance. Disease control measures in LMICs must take into account the persistent significant infant mortality and increased disease burden associated with HIV infection and exposure.

Prevalence of B. pertussis infection in children with clinically suspected pertussis

BACKGROUND

Pertussis is an important cause of hospitalization in children. Limited data on pertussis have been reported from China. The aim of this study was to characterize clinically suspected pertussis attributable to Bordetella pertussis among children and determine factors associated with longer duration of hospital stay in B. pertussis infection.

METHODS

Two hundred and seventeen consecutive children with clinically suspected pertussis were prospectively enrolled in the study between Jan 2016 through Aug 2017. Variables assessed included demographics, clinical symptoms and laboratory findings. Cox proportional hazards regression model were used to predict variables associated with longer duration of hospital stay.

RESULTS

Among the 217 patients with clinically suspected pertussis, B. pertussis was found in 106 (48.8%) patients. Of the 106 children with B. pertussis infection, 63 (59.4%) patients had coinfections with majority due to rhinovirus (HRV) (30.2%), Mycoplasma pneumoniae (29.2%) and human bocavirus (hBoV) (11.3%). Presence of coinfection [odds ratio (OR): 1.73, CI: 1.17-2.54], age ≤ 3 months (OR: 1.51, CI: 1.09 to 2.27), and WBC count ≥30 × 10⁹/L (OR: 1.66, CI: 1.07 to 2.84) were independently associated with a longer hospital stay.

CONCLUSIONS

B. pertussis infection had a high coinfection rate with the majority of coinfections due to HRV, M. pneumoniae and hBoV. Presence of coinfection, Age ≤3 months and WBC count ≥30 × 10⁹/L were associated with a longer hospital stay. Children admitted with pertussis need close monitoring when they had evidence of coinfection, Age ≤3 months, WBC count ≥30 × 10⁹/L.

Pertussis in infants, in their mothers and other contacts in Casablanca, Morocco

BACKGROUND

In recent decades, there has been a marked increase in the number of reported cases of pertussis around the world, and pertussis continues to be a frequently occurring disease despite an effective childhood vaccination. This study aims to determine the role of household contacts of children diagnosed with pertussis in Casablanca Morocco.

METHODS

From November 2015 to October 2017, children suspected of whooping cough that consulted Ibn Rochd University hospital at Casablanca with their household contacts were enrolled in the study. Nasopharyngeal (NP) samples of the suspected children were analyzed by culture and RT-PCR. For the household contacts, NP and blood samples were collected and analyzed by RT-PCR and specific detection of pertussis toxin antibodies by ELISA, respectively.

RESULTS

During the study period, the survey was carried out on 128 infants hospitalized for pertussis suspicion and their families (N = 140). B. pertussis DNA was specifically detected in 73 (57%) samples, coexistence of B. pertussis and B. parapertussis DNA in 3 (2.3%) samples, coexistence of B. pertussis and B. holmesii DNA in 10 (7.81%) and only one (0.78%) sample was IS 481 RT-PCR positive without the possibility of determining the Bordetella species with the diagnostic tools used. Confirmations of Pertussis infection in household contacts by culture, RT- PCR and serology were 10, 46 and 39%, respectively. B. pertussis DNA was confirmed in the infants as well in their mothers in 38% of the cases. Co detection of B. pertussis and B. parapertussis DNA in 2% and co-detection of B. pertussis and B. holmesii DNA in 4%. B. holmesii DNA alone was detected in 5 NP samples of index cases and their mothers.

CONCLUSIONS

The results of this study confirm that B. pertussis is still circulating in children and adults, and were likely a source of pertussis contamination in infants still not vaccinated. The use of RT-PCR specific for B. pertussis in the diagnosis of adults is less sensitive and should be associated with serologic tests to improve diagnosis of pertussis and contributes to preventing transmission of the disease in infants.

Pertussis seronegativity in pregnant women in the city of Al Ain, United Arab Emirates

OBJECTIVE

As the current recommendation of administering Tdap (tetanus-diphtheria-acellular pertussis) to all pregnant women has not been widely implemented in the United Arab Emirates (UAE), we aimed to ascertain the prevalence of pertussis seronegativity during pregnancy.

METHODS

IgG antibodies against Bordetella pertussis toxin (PT) were measured in 213 women attending the antenatal clinic at Oasis hospital, Al Ain, UAE. Results were compared by maternal age, nationality and gestational age with the Kruskal-Wallis test for IgG-PT levels and the Chi-squared test for serology status.

RESULTS

The mean age±SD of the participants was 30.4±5.6 years, mean gestational age±SD of 25.5±3.3 weeks. Serum concentration of IgG-PT <10IU/ml were found in 160 out of 213 women (75%; 95% confidence interval 69%, 81%). There was no significant difference in the geometric mean of serum IgG-PT concentration across maternal age (P=0.80) or nationality (P=0.90). There were no differences in the prevalence of seronegativity with maternal age (P=0.65) or nationality (P=0.90).

CONCLUSION

With a high prevalence of pertussis seronegativity in pregnant women, there is a potential benefit of introducing pertussis vaccination during pregnancy into our national immunization program.

Pertussis epidemiology in Tunisian infants and children and characterization of Bordetella pertussis isolates: results of a 9-year surveillance study, 2007 to 2016

PURPOSE

Pertussis remains a public health concern in most countries. Our study aimed to prospectively explore the epidemiology of pertussis in the Tunis area of Tunisia between 2007 and 2016, and to characterize the virulence-associated genes of the collected Bordetella pertussis isolates.

METHODOLOGY

Infants and children hospitalized at the Children's Hospital of Tunis, Tunisia, between 2007 and 2016 for suspicion of pertussis were enrolled in the study. Culture and real-time PCR (qPCR) assays targeting IS481, IS1001, recA, H-IS1001 and ptxP were used to confirm the pertussis diagnosis. Phenotypic and genotypic characterization of recovered isolates was performed.Results/Key findings. A total of 1844 children were included in the study. Overall, 306 children (16.6 %) with Bordetella infection were confirmed by qPCR. Among them, 265 (86.6 %) were confirmed as having B. pertussis (IS481+, ptxP+, H-IS1001-), 18 (5.9 %) as having Bordetella parapertussis (IS481-, IS1001+) and 11 (3.6 %) as having Bordetella spp. (IS481+, ptxP-, H-IS1001-). No Bordetella holmesii (IS481+, IS1001-, H-IS1001+) was identified. The estimated pertussis incidence in the Tunis area was 134/100 000 in children aged less than 5 years. Two epidemic peaks were observed in 2009 and 2014. Ten B. pertussis isolates were cultured and characterized. Deficiency in pertactin expression was not observed, and genotyping of the isolates revealed a predominant allelic profile: ptxP3-ptxA1-prn2-fim2-1-fim3-2.

CONCLUSION

This study demonstrated that pertussis is still present as a cyclical disease in Tunisia, despite high primo-vaccination coverage with a pertussis whole-cell vaccine. The predominant genotype of Tunisian B. pertussis isolates is similar to isolates circulating in countries using the acellular vaccine.

Pertussis in Africa: Findings and recommendations of the Global Pertussis Initiative (GPI)

Pertussis remains a major cause of morbidity and mortality, particularly in infants and young children, and despite the availability of vaccines and pertinent national and international guidelines. The disease burden is more severe in low- and middle-income countries (LMICs), especially in the African continent. Pertussis is more prevalent among young infants in Africa. Poor or no pertussis surveillance, lack of disease awareness, diagnostic limitations, and competing health priorities are considered key contributory factors for this high pertussis burden in Africa. Most African countries use whole-cell pertussis (wP) vaccines, but coverage with three primary doses of diphtheria-tetanus-pertussis vaccines falls short of the World Health Organization's recommended goal of >90%. The Global Pertussis Initiative (GPI) works toward developing recommendations through systematic evaluation and prioritization of strategies to prevent pertussis-related infant and child deaths, as well as reducing global disease burden to acceptable national, regional, and local levels. For countries using wP vaccines, the GPI recommends continuing to use wP to improve primary and toddler booster vaccination coverage. Vaccination during pregnancy is the next priority when acellular pertussis (aP) vaccines and other resources are available that directly protect newborns too young to be vaccinated, followed by, in order of priority, booster doses in older children, adolescents, healthcare workers and finally, all adults. Improved surveillance should be a high priority for African LMICs assessing true disease burden and vaccine effectiveness to inform policy. More research is warranted to evaluate the safety and efficacy of wP and aP vaccines and strategies, and to determine their optimal use.