The Value of the Second Shot

According to the most recent data from the Vermont Department of Health, nearly 37,000 people in Vermont have received only the first dose of a two-dose vaccine. Certainly, a handful of these people are not yet due for their second shot. They are waiting for the required 3 or 4 weeks to receive their second dose. The rest appear to be putting it off. I am here to share the value of getting the second dose.

One dose is not enough. The two shots of a two-dose vaccine are designed to work as a pair. The first shot provides the warning and the tools your immune system needs to handle the threat. The disease-fighting antibodies your body makes after the first vaccine decline after a short while. The second shot, given 3 – 4 weeks later, is like a drill for the actual infection. It provides your body with a better memory for the intruder. In the case of some vaccines, this memory can last decades or even a lifetime. Together, the two shots work much better than one. For example, one shot of Pfizer is 52% effective, while two are 95% effective. Similarly, according to the Food and Drug Administration, the Moderna vaccine can provide 80.2% protection after one dose, compared to 95.6% after the second.

Needing two shots is normal. You may not remember, but many of the vaccines you received as a child required two or more doses. It’s a normal part of how vaccines are designed, and it works great.

But what about side effects? You are right. People are more likely to feel lousy after their second dose of COVID-19 vaccine. You might have a headache, a fever, or fatigue. These are signs that your body is reacting quickly, which is just what we would hope it would do. (Note that not having side effects doesn’t indicate that the vaccine did not work.) This vaccine-induced feeling will last a day or two and is much milder than an actual COVID infection. In short, the temporary side effects of a vaccine are well worth the long-term protection.

But what if I had COVID? Isn’t my first shot like a second shot? If you already had COVID, your first shot is more likely to come with the side effects that some others experience after their second shot. More research is needed, but it is still recommended that you get your second shot. Recent data indicates the level of antibody and amount of time antibody persists after COVID infection is much less than what the vaccines elicit. We are not at all sure that infection is an adequate replacement for a vaccine.

I missed my second dose. What should I do? If you have already missed your chance to get your second dose at the recommended time, 3 weeks after the first dose for Pfizer and 4 weeks after for Moderna, try to get your second dose within 6 weeks of your first one. Within this period, the vaccines are believed to be about as effective as they are if given exactly as recommended. If you’ve missed the 6-week mark, get your second dose as soon as you can.

It’s easy. Locally, getting your second dose of COVID-19 vaccine is so easy. You can walk in, no appointment needed, to SVMC’s Respiratory Evaluation Center/ExpressCare in Bennington 8 a.m. – 6 p.m. any day, even weekends, for a first or second dose of Pfizer. Moderna is available 8 a.m. – 6 p.m. on Tuesdays and Thursdays. At this time, it is recommended for people to receive the same vaccine for their second shot as they received for their first one.

Marie George, MD, FIDSA, is the infectious disease specialist at Southwestern Vermont Medical Center and a member of the Dartmouth-Hitchcock Putnam Physicians.