Editor’s note: Dr. William Miller, chief of staff at the Adventist Health Mendocino Coast Hospital, is writing weekly reports concerning the COVID-19 situation on the Mendocino Coast. We are pleased to be running his health column, with details on the medical fight against the pandemic. The views shared in this weekly column are those of the author, Dr. William Miller, and do not necessarily represent those of The Mendocino Voice or of Adventist Health.
On August 31st, the FDA amended its emergency use authorization for both the Pfizer and Moderna COVID vaccines to now include a second component targeted specifically at Omicron. The vaccines will include the original component which targeted the original strain of COVID and still provides a fair amount of protection. The Pfizer vaccine is authorized for use as a booster to the original series in people aged 12 and older. The Moderna is authorized for ages 18 and up. Both shots are to be used as boosters, not as the original series and should be given at least two months after the last shot.
The reason that this is thought to be important is that the original vaccine had less effectiveness against the current Omicron variant. However, it is still quite effective at 68%. The new addition to the vaccines specifically targets the two most common subtypes of the Omicron variant, BA.4 and BA.5. These are causing most infections currently and are expected to remain the dominant subtypes through the upcoming winter months.
The side effect profile is the same for the new bivalent vaccines as it was for the original vaccines. That is to say that they are considered to be very safe. Of course, there are those that would contest this statement. However, this remains what is supported by valid science.
The current thinking by most public health authorities is that we will need to continue to get repeat booster shots for COVID for the indefinite future. This is because of our own immunity declining after vaccination or a COVID infection. Antibody levels begin to fall after about 3 months. However, that does not mean that there is no immunity, just perhaps less so. The problem with this figure is that circulating antibody levels do not necessarily correlate with immunity. After all, our body does not continue to produce any antibody at full steam forever. All antibody levels generally drift down to some lower level with time. Having said that, people can get a second case of COVID after an original infection. These infections are usually much milder as one would expect.
There is much debate over how often we will need to get booster shots moving forward. The expert opinions range from every 2 months (which in my opinion is extreme), to every 6 months to once a year. If the current variant does not change and continues to cause generally milder disease, it seems that twice a year is reasonable. If a person is at high risk due to age or other illnesses such as lung disease, then three times a year might be a better choice. As with all things medical, it is best to discuss this with your primary care provider. The bivalent vaccine is available now through most locations in Mendocino County that have been providing the previous vaccines.