Glenn Ellis: An update on various COVID-19 vaccines

Never before has such a large-scale vaccine rollout taken place with such urgency and aimed at so many people. There are currently two COVID-19 vaccines authorized for use in the United States, which require a two-dose series — Pfizer and Moderna. On Feb. 27, the Food and Drug Administration (FDA) issued an emergency use authorization for Johnson & Johnson’s (J&J) one-dose COVID-19 vaccine. Are they different in what you can expect for protection for each one? What’s next? A booster vaccine down the road?

Let me begin by letting those who are just hearing about the Johnson & Johnson vaccine what stands out about it. In addition to not requiring the extreme temperatures to be kept frozen until use, it is shown to be 85% effective in protecting you from getting a “symptomatic infection,” and there were no hospitalizations or deaths among people in large clinical trial the received the vaccine.

Both Pfizer and Moderna vaccines were effective, at least in the early stages, after vaccination. When these two vaccines were first tested, there was a rather weak immune reaction a few weeks after people in the trials received their first dose of vaccine. An even more impressive result happened when a second dose was given. The next set of trials specifically looked at the ability of the vaccines to prevent COVID-19 infection after receiving the two doses of vaccine. Although the vaccines were highly effective in preventing infections that cause symptoms after both the first and second doses, in these trials, a second dose was always given. It is not known how well the vaccine works if only one dose is given.

Multi-dose vaccinations are very common. In fact, nearly all vaccines recommended for children and adolescents and many adult vaccinations require a series of more than one dose. The recommendations from the Centers for Disease Control and Prevention (CDC) recommend that “the second dose of the COVID-19 vaccine be given within three weeks of the first dose for the Pfizer vaccine and within four weeks for the Moderna vaccine. No more than six weeks should lapse between doses, although if the second dose is not given during these time frames, it can be given without the need to repeat the first dose. It is not recommended to give the second dose any earlier than stated above, but if a person needs to get the second dose earlier, giving the second dose up to four days ahead of schedule is allowed.” CDC guidance actually permits some flexibility in “exceptional situations in which the first-dose vaccine product cannot be determined or is no longer available.” Now, researchers around the world are looking into the efficacy of single doses of mRNA vaccines.

Although 80.5 million vaccine doses have been administered in the United States, and the single-dose Johnson & Johnson vaccine is entering the U.S. supply, the demand for vaccines still far outpaces the number of vaccines available. That has led to those rather “interesting” global conversations about resorting to just giving everyone one dose to ensure an adequate supply to reach herd immunity. Former President Trump’s surgeon general, Dr. Jerome Adams, said in a tweet that the good protection available with one shot “is better than great protection for a few.”

In fact, since late December 2020, the United Kingdom has not told people to skip the second shot, but it has delayed the second doses of the Pfizer vaccine to prioritize first doses. The delay meant that the interval between doses could be extended up to 12 weeks instead of about three. Last week, Dr. Anthony Fauci told The Washington Post that there are “risks on either side” of switching to a single dose or sticking with the two. However, many medical experts and scientists worry this “single-dose strategy” could lead to more coronavirus variants and create more doubt and confusion during an already complicated vaccine rollout.

One of the biggest vaccine campaigns that supports the single-dose strategy was in Israel’s largest hospital where researchers looked at what happened after 7,000 staff was vaccinated with the first dose of the Pfizer vaccine. By the second to fourth week after they got the first shot, rates of symptomatic infection were down by 85%. So a one-dose COVID-19 shot is definitely in my “crystal ball” for the future as we work our way out of this pandemic moving toward herd immunity.

Finally, a word on the variants. The COVID-19 vaccines in the market and in development train the immune system to detect proteins on the surface of virus as the most effective vaccine target. However, mutations to the spike protein underlie the main variants causing concern. And like many things about the United Stated health care system, unlike some countries, the U.S. does not have any sort of nationwide COVID-19 surveillance program to identify variants.

There’s evidence that the Pfizer and Moderna vaccines currently being distributed are less effective against the new COVID-19 variants from South Africa and Brazil. That could change even more: each time a copy is made, the virus has a chance to accumulate more mutations that help them evade vaccines or spread more effectively. But there’s another way a COVID-19 virus could change really rapidly, in a sort of nightmare scenario. Fauci said the arrival of these new variants, particularly from South Africa, is a “wake-up call.”

While current data shows the two COVID-19 vaccines authorized in the U.S. offer good protection against the new variants, the FDA issued guidance earlier this week that will help vaccine makers respond more quickly to emerging variants, if needed. Moderna and Pfizer recently announced that they have begun to test a booster shot that targets the variants.

While we continue to sort this all out, and wait for enough of us to get our vaccination, the best advice? Everyone over the age of two should wear a face mask; stay at least 6 feet (about 2 arm lengths) from others who don’t live with you; and avoid crowds and poorly ventilated spaces. The more people you are in contact with, the more likely you are to be exposed to COVID-19 – whether you’re vaccinated or not. To your doctor take care of a COVID-infected patient, it won’t matter which strain you were infected with; your risk of getting very sick and possibly dying, may be the same.”…