Please note that this information is not meant to replace medical advice from a healthcare professional regarding benefits and risks of the vaccine for individual patients.
In November, we published information to help you understand the potential timeline for COVID-19 vaccine distribution. We also covered the efficacy and safety of the Moderna and Pfizer vaccines. Since that time, both vaccines have been approved for emergency use authorization (EUA), and the Janssen division of Johnson & Johnson has submitted an application for EUA of its vaccine. As cases of COVID-19 caused by variants of the virus increase, questions have been raised regarding the protectiveness of these vaccines against these variants. With so much new information, we wanted to provide a second COVID-19 vaccine Q & A.
The Moderna and Pfizer vaccines received EUA in December 2020. Last week, Johnson & Johnson submitted an application for EUA which is expected to be granted before the end of February 2021. The Johnson & Johnson vaccine has some logistical advantages compared with the Moderna and Pfizer vaccines. It does NOT need to be stored at ultra-cold temperatures, and it is expected to be authorized as a single shot rather than two shots required for the Moderna and Pfizer vaccines.
Two other manufacturers, Novavax and AstraZeneca, are in final phase trials in the United States, and are expected to apply for EUA in the spring.
Our focus throughout the remainder of the Q&A will be on vaccines manufactured by Moderna, Pfizer, and Johnson & Johnson.
Springbuk’s ultimate goal is to prevent disease with data. With that in mind, we are working to develop reports that will help you track COVID-19 vaccinations among your employees and their families. While vaccinations could be underreported through claims, we have already received a substantial number of claims for both the Pfizer and Moderna vaccines.
Information used to track vaccinations may be available in drug claims and/or medical claims. Both National Drug Codes (NDCs) and CPTⓇ codes exist that identify the specific vaccine product. Additionally, CPTⓇ codes exist for the cost of administering the vaccine. Provided claims are submitted, we can track these vaccinations through claims for either the product itself or the administration codes.
Vaccine efficacy reported in the news is generally a measurement of the vaccine’s ability to prevent symptomatic disease. Those symptoms range from milder ones to symptoms severe enough to require hospitalization. But manufacturers also report what is arguably a more important measure, the ability of the vaccine to prevent hospitalization and death.
The good news is that all of the vaccines are highly protective against hospitalization and death. Moderna and Johnson & Johnson report being 100% protective against these serious outcomes. Pfizer reported one hospitalization due to COVID-19 among the 37,706 individuals in the vaccinated group.
Where the vaccines may differ is in their ability to prevent milder forms of disease. Moderna and Pfizer each reported about 95% efficacy in preventing symptomic disease, while J&J reported 72% efficacy in their United States trial.
Experts caution against comparing these efficacy rates. To have a true apples to apples comparison, the trials would need to occur at the same time in the same locations. Johnson & Johnson completed trials several months after Moderna and Pfizer, and may have been impacted by variants of the virus that cause COVID-19.
Many public health experts are urging individuals to receive the first vaccine available regardless of efficacy. Waiting for a vaccine that may be slightly more effective at preventing symptomatic disease leaves individuals at risk for getting potentially serious COVID-19 disease in the interim.
As viruses replicate, they often make mistakes that lead to changes in the virus’s genetic code. These mistakes or mutations are common among all viruses, including the virus that causes COVID-19. Combinations of mutations that provide advantages to the virus are more likely to persist. When a specific group of mutations causes the virus to behave differently from the original strain, it is referred to as a variant.
Variants are common, but we usually only hear about variants that begin to make up a significant portion of infections. A number of variants that were initially identified in other countries have been detected in the United States, including B.1.1.7, more commonly known as the UK variant, and B.1.351, better known as the South African variant, and P.1, better known as the Brazilian variant. In January, the CDC predicted that the UK variant could become the dominant strain in the United States by March. Because this variant has been shown to spread more quickly, the result may be another surge in cases.
A common misconception is that vaccines are either fully protective or not protective. Instead, we should think of a vaccine’s effectiveness along a continuum where the best ones might eliminate all symptomatic disease and transmission; while those that are still considered protective, but are at the other end of the continuum, prevent only the most serious outcomes. A vaccine would no longer be considered protective if it falls off this continuum altogether, unable to prevent any form of symptomatic disease.
A small change in the genetic make-up of the virus may have minimal impact on the protectiveness of a vaccine. Still, eventually, accumulated changes may cause the vaccine to become substantially less effective or ineffective.
So what do we know so far about how protective the vaccines are against the new variants?
Both Moderna and Pfizer are already planning studies to determine whether a booster shot, possibly tweaked to be specific to the new variants, would be beneficial.
The amount of time individuals will remain immune is unknown at this time. We do know that some vaccines for other conditions provide life-long immunity (e.g., measles), some require occasional booster shots (e.g., tetanus), and others need to be administered annually (e.g., influenza).
One factor that impacts how often a vaccine needs to be given is the “durability” of the immune response – the length of time that the elicited immune response remains strong. If this response wanes over time, there is an increased risk that vaccinated individuals will become susceptible to symptomatic disease. We don’t have this information yet, but analyses of longer term data being collected by the manufacturers should provide better estimates of how long individuals remain protected.
The second factor is whether the virus mutates in a way where the antibodies are no longer effective against the virus, as discussed in the previous questions. While evidence so far indicates that the vaccines are still protective against known variants, the decrease in effectiveness against the South African variant has caused many experts to believe that booster shots will become necessary at some point.
Results from the Pfizer, Moderna, and Johnson & Johnson trials demonstrated that individuals who received the vaccine were less likely to become sick with COVID-19. But the trials did not evaluate whether these vaccinated individuals were able to spread the virus despite not having symptoms. Because of the major role asymptomatic spread has had in unvaccinated individuals, the possibility of similar spread by vaccinated individuals remains. Currently, there is a lack of consensus as to the likelihood that vaccinated individuals could be protected from disease, but still be able to transmit the virus.
We also know that while the vaccines are effective, they are not 100% effective. Erring on the side of caution has led to recommendations for vaccinated individuals to continue with current mask and social distancing protocols to protect themselves and others.