Q: What happens if I skip my second vaccine dose?
A: If you are receiving either the Pfizer or Moderna COVID-19 vaccines, and you skip your second dose, you will have less effective protection against the disease and any existing or future variants of the virus that are likely to continue to spread throughout the world, according to public health experts.
You should only bypass your second dose if you have a severe allergic reaction to the first and are medically advised to skip the second by your physician, according to the U.S. Centers for Disease Control and Prevention.
Otherwise, you should get your second dose of the vaccine.
Dr. Paul Offit, a vaccine expert and a professor at the University of Pennsylvania, explained in an educational video that the second dose of the Pfizer or Moderna vaccines provides both longer lasting protection against SARS-CoV-2 as well as better protection against variant strains of the virus.
The researchers conducting the earlier trials of the vaccines “found that when they gave that second dose, there was a dramatic increase in the level of neutralizing antibodies, so they’re compared very favorably to that found after a natural infection. In fact, it was in many ways higher than that found after natural infection,” Offit said. “The second dose gives you much better and likely longer-lasting immunity than a first dose alone would give you.”
The CDC has reported that as of April 9, about 5 million people have missed their second doses of either Pfizer’s or Moderna’s COVID-19 vaccine, or about 8% of all people who had received first doses as of that time. Some people have skipped because they were worried about side effects of the second shot or else were unable to find a second dose or make their follow-up appointment.
Some people who receive the Pfizer or Modern vaccines may notice stronger side effects after their second dose because the body’s immune response is already primed to respond to the vaccine. The most common side effects are fatigue, headache, muscle aches and fever, but these side effects will typically go away within a few days days, and public health experts agree that for the majority of adults, the benefits of the vaccine outweigh the risks of getting infected with SARS-CoV-2.