Two COVID-19 vaccines with Emergency Use Authorization (EUA) from the Food & Drug Administration (FDA) have started to arrive in Wyoming. Supplies are limited, and vaccines are initially being given to healthcare workers involved in direct patient care, and residents of long-term care facilities. The vaccines will be distributed at no cost, and initially based on a tiered prioritization schedule, which can be found on the Wyoming Department of Health website: https://health.wyo.gov/wp-content/uploads/2020/12/Updated-COVID-19-Vaccine-Priorities-Phase-1a-December-22-2020.pdf
These vaccines made by Pfizer and Moderna are both mRNA vaccines. The technology used to make them has been in development for approximately 30 years, but there has been increased interest in the past decade. The reason mRNA vaccines are an attractive option for a pandemic, is that mRNA production can be accomplished extremely rapidly. Unlike traditional vaccines, the virus does not need to be grown in tissue or eggs.
Messenger RNA, mRNA for short, encodes a message that is read and made into a protein. The mRNA in the vaccine contains the code to make part of the spike protein of the SARS-CoV-2 virus, not the whole virus. The spike protein is the key which unlocks our cells for infection. After the vaccine is injected into a muscle, a lipid or fat bubble is used to carry the mRNA inside of a cell. Once inside the cell, mRNA is used to generate the protein, and then it is rapidly broken down. It’s this protein that the immune system recognizes to fight the virus.
The immune response can be somewhat intense. If it didn’t do this, it wouldn’t be effective. You might get a fever, muscle and joint pain, and redness, pain and swelling at the site of injection. This may be worse after the second dose, and it is normal. There is no chance that the vaccine can give you COVID-19, the instructions aren’t there, the virus is not being made. I’ve been asked about the possibility that the mRNA vaccines will change your DNA. It just can’t happen, it never gets into the nucleus of the cell, it has no means to integrate into DNA.
Some people are concerned about how rapidly these vaccines were approved for EUA. It was a priority to get out an effective vaccine as quickly as possible, but this does not mean that any corners were cut in the process. The regulatory process of the FDA was streamlined, and there was a large pool of willing subjects for the vaccine trials. They have been shown to be effective and safe.
Two doses of vaccine are required to get the full benefit. The second dose of the Pfizer vaccine is given 3 weeks after the first dose, and the second dose of the Moderna vaccine is given 4 weeks after the first dose. The vaccines are not interchangeable, and the same vaccine should be given for both doses. It then takes another 10-14 days after the second dose to build full immunity.
Both vaccines have shown to be approximately 95% effective. They are generally well tolerated with severe adverse events being rare. Neither vaccine contains any preservatives, which are often felt to be the source of side effects from vaccines. Pfizer is approved for persons 16 years of age and older, Moderna for persons 18 years of age and older. Both are now testing in persons 12 years of age and older.
Will I take one when offered? Yes, absolutely.
But the virus has already mutated, won’t this just make these vaccines obsolete? The virus has not mutated enough to impact the effectiveness of the vaccines. If the virus were to mutate in just the right way to avoid the immune system, it would take a few days to recode the mRNA and put that into the vaccine. Again, much faster than growing the new virus in culture media.
There are many other vaccines still in trials, I’ll mention a couple. Janssen is the pharmaceutical arm of Johnson & Johnson, and they have a vaccine in Phase 3 testing for both a one dose and two dose regimen. This is an adenovirus-based vaccine. They just had an Ebola vaccine approved using the same biotechnology. AstraZeneca just received EUA in the UK for the vaccine they made in collaboration with Oxford. This is also an adenovirus-based vaccine, and they are in the middle of Phase 3 trials in the US. These are more stable than the mRNA vaccines and can be stored much more easily with just refrigeration.
Vaccine safety has been and will continue to be a top priority of the Centers for Disease Control (CDC). V-safe is a smart-phone based tool that uses text messaging and web surveys to provide personalized health check-ins once someone receives a COVID-19 vaccination. You can report any side effects after getting a COVID-19 vaccine, and the CDC may follow up by phone to get more information. V-safe will also remind you to get your second dose. You can sign up here:
We need to use all our tools to put an end to this pandemic. Once you get the vaccine (or have had a natural infection), it’s important to continue to wear a face covering, social distance and wash your hands frequently. If you get the vaccine and subsequently come into contact with SARS-CoV-2, your body will know how to fight the virus, and helps prevent severe illness requiring hospitalization. We do not know yet whether a vaccinated person (or someone who has had previous infection) can still carry the virus and spread it to someone else.
How frequently will we need to get vaccinated? Once we know how long the immunity lasts, we will be able to answer that question. Until now, studies have shown that antibodies last 3 months. That’s because that is how long the studies lasted. Now that more time has passed, longer studies are coming out, and showing that the antibodies are lasting at least 8 months. It’s likely that antibodies will last even longer. People who have had COVID-19 infection, whether they had symptoms or not, should still get vaccinated.
These vaccines represent hope. Everyone who is able to get vaccinated should do so when it is their turn. The alternative is that this pandemic continues, and lives continue to be lost.