Pfizer CEO Albert Bourla announced that booster shots of COVID-19 vaccines will likely be needed within 12 months of the initial doses.
As countries around the world roll out their vaccination programs, a sense of relief is slowly taking over. Current COVID-19 vaccines either follow a two-dose regimen or a single dose one. However, it is unclear as to how long protection will last from the current vaccines. According to Pfizer CEO Albert Bourla, there is a possibility that booster shots of these vaccines will be required within 12 months of the initial doses.
Earlier this month, Pfizer revealed that its COVID-19 vaccine is 91% effective for up to six months after the second dose, and 95% effective against severe disease. However, Pfizer and BioNTech are further analyzing the data to identify whether immunity lasts after six months. The results are from the phase 3 study that included more than 12,000 vaccinated participants.
A booster shot is just a repeat dose of the vaccine; given after initial immunization to enhance your immunity. Repeated exposure to the immunizing antigen leads to the immune system creating more memory cells and antibodies. Booster shots are generally given for diseases that mutate at a fast rate, or those against which our body’s immune response wanes with time. For example, the tetanus vaccine requires a booster shot every 10 years, as the immunity weakens after that time period. Furthermore, the flu virus mutates itself every year; therefore, a booster shot is required every year for protection.
Just Like an Annual Flu Shot
According to a White House official, Dr David Kessler, the neutralizing antibodies decline slowly after the second dose of an mRNA vaccine. Moreover, the rise in variants pose a threat to the antibody response.
Similar to Pfizer, Moderna’s vaccine has also shown immunity lasting for six months. However, experts believe that the new variants may lead to the need for regular boosters, similar to the annual flu shots. Pfizer is currently testing a third dose of its vaccine.
On the other hand, Moderna is aiming to combine a COVID-19 vaccine with a flu shot. The combination will likely provide protection against both a COVID variant of concern and a seasonal flu strain.