Third Dose: A Necessity or a Luxury?
If you have been vaccinated against COVID this year, it is very likely that you may have received an mRNA-targeting vaccine, developed by either Pfizer or Moderna pharmaceutical companies. To be fully protected against COVID, you were required to receive two shots of the Pfizer or Moderna vaccine, a few weeks apart from each other - or in some countries, like Canada, a few months apart. The initial data regarding those vaccines guaranteed safety and protection against the virus, with protection rates estimated to be 95% against infection and 100% against severe hospitalization. However, in recent weeks, the development of new variants of COVID urged health experts to investigate their potential impact on vaccinated individuals.
The Delta Variant: an early warning sign
The most emerging variant, referred to as the Delta variant, stood out to scientists and experts as evolving data is showing that it could be highly infectious for both unvaccinated individuals and those who received their vaccines earlier than six months of date of exposure. Officials at Pfizer are suggesting that the immunity levels provided by the vaccine may decrease after six months, especially against new variants. In preliminary data collected in Israel during June and July of this year, merely 65% of individuals who received their vaccine over 6 months ago were protected against the Delta variant, as opposed to earlier data that showed an initial protection rate of 95% when first receiving the vaccine.
A quick call for action
The preliminary data urged officials at Pfizer to request the green light for an expedited emergency review by the Food and Drugs Administration in the US for the approval of a third booster shot. It is argued that a third booster shot, administered after six months of the second shot, could help increase antibody levels and hence immunity protection against COVID and its quickly developing variants. Following this rationale, some countries already began administering the third booster shot very recently. For instance, Israel began administering a third dose of the vaccine to vulnerable populations, including elderly and those with chronic diseases like cancer.
But the story is different in the US. The CDC released a press statement following Pfizer’s request, and reiterated that vaccinated Americans continue to be protected and that there is no data to suggest otherwise as of now. Additionally, the statement stressed that the vast majority of infections and hospitalizations occurring due to COVID continue to be among individuals who did not receive a vaccine. This information was echoed by Dr. Anthony Fauci, the serving COVID-19 federal advisor as the director of the National Institute of Allergy and Infectious Disease. Dr. Fauci, in a recent statement to CNN just this past weekend, stated that given the data and information at this point, there is absolutely no need to urge people to receive any additional shots.
Regardless of whether a third booster shot will be proven valuable, the message that everyone agrees on is that variants may be a subtle threat arriving to our horizon, profoundly complicating our battle with the pandemic. COVID variants arise due to infections occurring rapidly, especially among non-vaccinated individuals. Areas with low vaccination rates continue to be considered epicenters and breeding grounds for variants. Regardless of future vaccination efforts, there is a strong call for reliable and up-to-date data so that we can understand our direction in the battle with the pandemic. Emerging data will answer the question everyone is asking in recent weeks regarding the newly evolving variants: are variants even worth watching, or should we be alarmed already?
References
Pfizer Pushes Ahead for Its Third Booster Vaccine Despite Conflicting CDC and FDA Statements. (2021). Retrieved 12 July 2021, from https://www.goodhousekeeping.com/health/a37002229/pfizer-third-covid-booster-vaccine/
Lieber, D. (2021). Pfizer Vaccine Less Effective Against Delta Infections but Prevents Severe Illness, Israeli Data Show. Retrieved 13 July 2021, from https://www.wsj.com/articles/pfizers-covid-19-vaccine-is-less-effective-against-delta-variant-israeli-data-show-11625572796
Anthes, E. (2021). Covid’s Lambda Variant: Worth Watching, but No Cause for Alarm. Retrieved 15 July 2021, from https://www.nytimes.com/2021/07/08/health/lambda-variant-covid-peru.html?searchResultPosition=7