Persistence of Immunogenicity of a Purified Inactivated Zika Virus Vaccine Candidate in Healthy Adults: 2 Years of Follow-up Compared With Natural Infection

BACKGROUND

We report 2-year persistence of immune response to Takeda's prophylactic purified formalin-inactivated whole Zika virus vaccine candidate (TAK-426) compared with that observed after natural infection.

METHODS

A randomized, observer-blind, placebo-controlled, dose-selection, phase 1 trial was conducted in 18-49-year-old adults at 9 centers (7 in the United States, 2 in Puerto Rico) from 13 November 2017 to 24 November 2020. Primary objectives were safety, tolerability, and immunogenicity of 3 increasing doses of TAK-426 administered as 2 doses 28 days apart to flavivirus (FV)-naive and FV-primed adults. Here, we report on safety and persistence of immunity up to 2 years after primary vaccination with 10-μg TAK-426, the highest dose, and compare neutralizing antibody responses with those observed after natural infection.

RESULTS

TAK-426 at 10-μg had an acceptable safety profile in FV-naive and FV-primed adults up to 24 months after dose 2. Seropositivity for neutralizing antibodies was 100% at 1 year, and 93.8% and 76.2% at 2 years in FV-naive and FV-primed groups, respectively. TAK-426 responses were comparable in magnitude and kinetics with those elicited by natural Zika virus infection.

CONCLUSIONS

These results support the further clinical development of TAK-426 for both FV-naive and FV-primed populations.

CLINICAL TRIALS REGISTRATION

NCT03343626.

Purified Inactivated Zika Vaccine Candidates Afford Protection against Lethal Challenge in Mice

In response to the 2016 global public health emergency of international concern announced by the World Health Organization surrounding Zika virus (ZIKV) outbreaks, we developed a purified inactivated Zika virus vaccine (PIZV) candidate from ZIKV strain PRVABC59, isolated during the outbreak in 2015. The virus isolate was plaque purified, creating six sub-isolated virus stocks, two of which were selected to generate PIZV candidates for preclinical immunogenicity and efficacy evaluation in mice. The alum-adjuvanted PIZV candidates were highly immunogenic in both CD-1 and AG129 mice after a 2-dose immunization. Further, AG129 mice receiving 2 doses of PIZV formulated with alum were fully protected against lethal ZIKV challenge and mouse immune sera elicited by the PIZV candidates were capable of neutralizing ZIKVs of both African and Asian genetic lineages in vitro. Additionally, passive immunization of naïve mice with ZIKV-immune serum showed strong positive correlation between neutralizing ZIKV antibody (NAb) titers and protection against lethal challenge. This study supported advancement of the PIZV candidate toward clinical development.

An international perspective on optometric education

In many of the world's nations, optometry hardly exists because resources are not sufficient to educate optometrists nor to fund their services. In others, tradition and accommodation with other forces have rendered optometry incapable of change that would expand its scope of services. But, in a growing number of countries, there is an accelerating trend toward expansion of education and scope of practice. Optometry is coming to be defined in those parts of the globe as that independent primary health profession whose practitioners are educated in vision and health sciences, and who meet standards that qualify them to diagnose and treat visual problems and ocular disease. Review of this change, wherever it has transpired, leads to the conclusion that the scope of optometric practice expands only after corresponding expansion in optometric education. These goals are being achieved in a group of highly developed countries in which optometry has long been a major eye care provider, and in countries in which socio-economic and political conditions are improving, but where there is no significant source or tradition of primary eye care of any scope.

The role and goals of academic optometry. Some unfulfilled missions

The authors express the opinion that optometry schools have obligations to the profession and the public which involve missions beyond their primary function of educating and training students. They identify those missions which they believe are highly important but only partially addressed. They are: clinical research; expansion of optometry's scientific base; specialized patient care; and education of practitioners. They offer explanations for lack of progress, but insist it is vital that these obligations be met by our schools, and offer suggestions toward this end.

A longitudinal study of corneal astigmatism and total astigmatism

Cross-sectional studies indicate that mean total astigmatism changes with age; varying from as much as 0.62 D with-the-rule during youth to as much as 0.37 D against-the-rule in samples of elderly patients. The present study involves the examination of adult patients who were seen regularly for a period of at least 40 years. Data are analyzed to determine whether the change in corneal astigmatism accounts for the total astigmatic change, and the magnitude of change with age at each of the principal corneal meridians. Results indicate that steepening of the cornea in the horizontal meridian accounts for a major portion of the increase in against-the-rule total astigmatism among older patients.

Erickson goniolens system

The Optometric Research Institute has clinically evaluated the effectiveness and efficiency of the Erickson Goniolens System. Operational procedures and interpreting the results are discussed. Advantages, disadvantages and conclusions are expressed.

What should be optometry's role? How should we prepare for it?

This is a position paper which broadly states the role which, in the author's opinion, optometry should adopt as its goal and the educational environment in which we can best prepare graduates to fulfill that role. The role briefly stated, is that of first contact supplier of vision care and of certain aspects of primary health care. The appropriate educational milieu is held to be the academic health center.