January 27, 2021
Much has been written about the safety and efficacy of vaccines, especially the COVID-19 vaccines. These vaccines have gone through an accelerated review process and are not approved for use, but authorized. While this difference may not mean a whole lot to those of us still anxiously awaiting our turn to be vaccinated, it is a difference for regulators, public health experts and for the companies hoping to get a vaccine on the market.
Vaccines are regulated by the US Food and Drug Administration. As with all medical products, the manufacturer of the product submits a package for review and the FDA staff work to evaluate the data submitted. The type of submission for vaccines is called a BLA - biologics license application. FDA has 10 months to review the application; six months if it is a priority review. BLAs require substantial evidence of effectiveness. The process of developing and getting a vaccine approved usually takes about 10 years in total.
However, in the case of COVID vaccines, the application was not a regular BLA, but an Emergency Use Authorization (EUA). The EUA provisions of the law allow the FDA to temporarily authorize products for a specific purpose during a public health (or other) emergency. EUAs can be issued when the product is effective and benefits outweigh risks. This is a lower standard than the normal BLA approval standard. This has also been a particularly speedy process - from the time the COVID virus was identified to having a vaccine on the market only took about a year.
Pfizer submitted its application for a COVID vaccine on November 20; Moderna submitted its application shortly thereafter. On December 10, FDA held an advisory committee meeting regarding the Pfizer application; on December 17, it held one regarding the Moderna application.
Advisory Committee meetings (AdComms) are not unusual proceedings for the FDA - they are meant to bring together outside experts to help advise the FDA on complicated issues. The FDA by and large follows the advice of the AdComm, although in rare instances it does not.
On December 11, 2020 FDA announced that it was issuing an EUA for the Pfizer-BioNTech vaccine, which is two doses taken three weeks apart.The decision was based on a two month follow-up data showing that the vaccine was 94% effective in reducing the incidence of COVID as determined by a test only after a participant has symptoms. Pfizer’s plan is to conduct follow up for 30 months. The vaccine is indicated for individuals 16 and over.The subgroup analysis showed that in almost 120 16-17 year olds, there was only one case of COVID, in the unvaccinated population. That is not enough data to determine if the vaccine is useful in that age group.
On December 18, 2020 FDA announced that it was issuing an EUA for the Moderna vaccine, which consists of two doses taken four weeks apart. The decision was based on a two month follow-up data showing that the vaccine was 94% effective in reducing the incidence of COVID. As a note, the study protocol did not test people who were asymptomatic, so the data do not show if the vaccine protects against mild or asymptomatic cases of COVID. Moderna’s plan is to continue follow-up for two years. The vaccine is indicated for individuals 18 and over.
Neither of these studies included pregnant women. The US Centers for Disease Control and Prevention (CDC) released guidelines that included pregnant women discussing the question of COVID vaccines with their provider. On January 25, 2021 the World Health Organization released a recommendation to not use a COVID vaccine on pregnant women, unless they are front line health care workers or have other comorbidities.
There are additional data to gather and more vaccines in the works. Studies are enrolling younger teens and it is expected that after the results of those studies, studies will be done on children. There are additional vaccine candidates on the horizon; notably, one from Johnson & Johnson that is a single dose vaccine.
States are currently responsible for the roll-out of vaccination plans. States have prioritized front-line health care workers and the elderly, but each state is making its own determination about who, exactly, is eligible when. Notably, states differ on prioritization of group facilities, such as nursing homes and prisons/jails, which have been hotbeds of COVID spread.
For some people, the question is not “when can I get the shot?” but “do I have to get the shot?”. Right now, there are no laws requiring COVID vaccinations, but they would likely be legal under the police power of the state, as interpreted by the Supreme Court in 1905. Many employers and schools are expected to require COVID vaccination for employees and students. This will likely be legal, although there are challenges. For example, if employers require their employees to get vaccinated and the employee has a reaction to the vaccine, the employer will be subject to a workman’s compensation claim from the employee. The EEOC has already released technical assistance stating that it believes that a vaccine authorized, rather than approved, will also be held to the existing legal standard. Any rules regarding mandatory vaccines will need to have exceptions for those whose health will be put at risk from the vaccination; religious exemptions may not hold.