Expert Q&A: When is the best time to catch up on vaccines?

As the calendar turns to a time of changing leaves, big sweaters, cups of apple cider, and trick-or-treating, faculty at the Perelman School of Medicine are also preparing for vaccine season.

Part of that preparation includes guidance on vaccines, including the updated COVID vaccine, which is of particular importance as COVID cases are beginning to surge, along with vaccines for other respiratory . When should you consider getting updated shots, which shots are necessary, and can you get the flu and COVID vaccines at the same time in the same arm? Here are some of the most frequent questions our experts see, according to Judith O’Donnell, MD, the associate chief medical officer for Health Epidemiology at Penn Medicine and the chief of Infectious Diseases at Penn Presbyterian Medical Center, and Neil Fishman, MD, Chief Medical Officer of the Hospital of the University of Pennsylvania.

“The colder days of late fall, winter, and early spring often correlate to higher circulation of respiratory illnesses like colds, the flu, and even COVID,” said O’Donnell. “People often spend more time indoors and in close quarters, and winter’s cold and dry air also can increase some bugs’ survivability inside and outside the body.”

If I have received a COVID vaccine and or if I’ve had COVID before, do I really need the updated vaccine to prevent infection?

The CDC recommends everyone older than six months receive the updated 2024-2025 COVID vaccine, which will provide protection against the COVID variants that have been commonly circulating throughout 2024. Immunity diminishes over time, and the vaccine provides an immune response that can decrease the likelihood of a new infection and decrease the likelihood of severe COVID-19 disease, hospitalization, and death.

Are these new COVID vaccines just as safe as they were at the start of the pandemic?

The updated 2024-2025 COVID vaccines are just as safe as the earlier vaccine versions. There are updated mRNA vaccines from Pfizer and Moderna along with a protein subunit vaccine from Novavax. Protein subunit vaccines are not new either and contain a protein from the virus that can trigger the immune system to produce specific antibodies to that virus. All are safe and effective.

Has our understanding of who should get COVID updated vaccines changed at all?

No. For the past three years, the CDC has consistently recommended that everyone older than six months get an updated COVID vaccine. It is especially important for individuals ages 65 and older, for anyone with a medical condition that puts them at high risk for severe COVID, and for those who have never received a COVID vaccine, to get vaccinated with the updated 2024-2025 vaccine.

When should I get the new COVID vaccine to protect me through the fall and winter?

Determining the right time to get a COVID vaccine depends on several things including your medical history, age, the timing of your last COVID vaccine dose, and when you last had a COVID infection. For example, people who have had COVID infection during the summer of 2024 or more recently should wait at least 3 months after their infection before getting the updated 2024-2025 COVID-19 vaccination. People should also wait at least 6 months from their last COVID vaccine before getting the updated version. Additionally, people who are taking medications that suppress the immune system may need to coordinate vaccination with administration of other medications. You should talk with your health care provider about the best time for you to get vaccinated this fall.

Is there any reason I should not get the flu vaccine at the same time as the updated COVID vaccine?

If I feel my body is extra sensitive to vaccines or I really have strong symptoms after vaccines, would spacing them out be best? (If yes, when should I do each one?)

The influenza vaccine and the updated COVID vaccine can both be given at the same visit. Typically, each vaccine would be given in a different arm. There is no medical reason to do them in different arms or to split up the timing of them. While it’s theoretically possible that side effects from both vaccines could be compounded, there is no real-world data to suggest this happens. The decision to separate timing of vaccines can be a personal choice left to the individual.

Also, October is the perfect time for the flu vaccine since it will trigger your immune system to prepare for the flu prior to flu season and likely will offer protection through the months when the flu is circulating the most.

Who should receive the RSV vaccine and the pneumonia vaccine?

Three RSV vaccines have been licensed and approved for adults in the U.S. RSV (respiratory syncytial virus) is a virus that can cause pneumonia and severe lower respiratory tract infections in older adults, and infants. CDC recommends everyone ages 75 and older get an RSV vaccine, and persons 60-74 who have additional risk factors that could lead to a severe infection, should also get an RSV vaccine. An RSV vaccine can be given at any time of the year. If you have never received it, then getting it in the fall is often a good time for vaccination, since winter is the typical RSV season. You only need to receive an RSV vaccine once in your lifetime.

The pneumonia vaccine protects people from pneumococcal pneumonia which is a type of bacterial pneumonia. Not all cases of pneumonia are pneumococcal pneumonias, and some are caused by viruses. But pneumococcal pneumonia is one of the more common causes of community-acquired pneumonias. Many people of all ages should receive the pneumococcal pneumonia vaccine, depending on underlying medical conditions. Talk to your health care provider to determine when the right time is for you to get the pneumococcal pneumonia vaccine.

Are there any extra considerations I should take regarding vaccinations around people with compromised immune systems?

If you live with, or spend a lot of time with, individuals with compromised immune systems, then it is important to stay up-to-date with all vaccinations that apply to you. This includes the vaccines for respiratory viruses like COVID, influenza, and RSV, along with other vaccines such as pertussis (Whooping cough) and pneumonia vaccines. Talk to your health care provider to make sure you are up-to-date with all adult immunizations.

I’m around a lot of children and babies who are always catching some kind of bug. Are there any extra vaccine considerations I should take to keep us both healthy?

Children and adults should both receive annual influenza vaccination and the updated 2024-2025 COVID vaccine. RSV vaccination in older adults who routinely care for infants should also be considered. Further good respiratory etiquette, including covering your mouth when coughing and sneezing, frequent hand hygiene, and staying home when sick, all can help prevent the spread of respiratory viruses when around children, particularly during the colder months.

Is there anything else that we need to know about the flu, COVID, circulating viruses, or vaccines as we move through the fall season?

Make a plan to get vaccinated. Viruses and other illnesses are always in circulation, but it is an especially dangerous time of year. And stay home when you’re sick. If you have to go out, put on a mask. These are some of the easiest and most straightforward ways to keep your loved ones, your community, and yourself healthier.