Also, some people may have medical conditions that render vaccines less effective at protecting them. These individuals depend on the rest of society — those who can receive the vaccine — to do so and try to prevent these diseases from spreading.
CNN: What about pregnant people? Are there also some vaccines they cannot get?
Wen: This is another good point. Take rubella, or German measles. Pregnant individuals cannot receive the MMR vaccine because it contains live virus. But rubella can be especially dangerous during pregnancy.
In addition to increasing the risk of miscarriage and stillbirth, rubella can lead to a condition called congenital rubella syndrome that can cause numerous birth defects including heart problems, brain damage, deafness, and lung, liver, eye and thyroid ailments. According to the World Health Organization, before the introduction of the vaccine, as many as 4 babies in every 1,000 live births were born with this condition. Rubella remains the leading cause of vaccine-preventable birth defects.
Pregnant patients should not receive other live-attenuated vaccines either. Varicella, the vaccine against chickenpox, is another one of these vaccines. People should receive the vaccines before they are pregnant, ideally as part of their routine childhood immunizations. And other people can help to reduce disease in the community by getting vaccinated themselves.
CNN: Who would be at highest risk if there is lower population-wide immunity?
Wen: There are three groups I would be the most worried about. First are newborns who are too young to be vaccinated. They are also among the most medically fragile; something that is a mild cold for an older child or healthy adult could send them to the hospital.
Second are immunocompromised people. This is a large group and includes patients receiving cancer treatments, transplant patients and individuals taking immunosuppressant medications. These individuals are more likely to become severely ill if exposed to disease. Vaccines may also not protect them as well, or they may be ineligible to receive certain vaccines as we discussed earlier.
Third are the elderly. As we discussed many times in reference to Covid-19, these are individuals whose age and underlying medical conditions make them more susceptible to severe illness. That, in combination with possible waning immunity from certain vaccines, could put them at higher risk if there is more disease in the community because of lower vaccine coverage.
CNN: What can be done to prevent this possibility?
Wen: Everyone should speak with their primary care provider to verify that they are up to date on recommended vaccines. Parents with young children should do this with their family’s pediatrician, and adults should also be sure to speak with their family physician or internist as well.
The reason to do this is primarily to ensure that you are well-protected. If you are eligible for additional booster doses, you may consider getting them, or, if you are more susceptible to certain illnesses because you are not eligible for some vaccines, you should also know this and take precautions accordingly.
There’s another reason: The entire concept of population immunity depends on all of us doing our part to keep diseases at bay. That protects us — and others around us, including those who are especially vulnerable to severe illness and death.
