Doctors believe there could be another “tripledemic” this winter with COVID-19, flu and respiratory syncytial virus (RSV) and are urging individuals to protect themselves by getting vaccinated.

David Cennimo, an infectious disease expert at Rutgers New Jersey Medical School, discusses what you need to know about the series of recommended vaccines.

What can we learn from last year’s flu season and what should we expect this year?
Most experts believe will see increased cases at least back to the level of a previously "normal" year before the pandemic. Physical distancing, closure of congregate activities and widespread masking during the pandemic did result in a decrease in respiratory viral transmission across the board. We had some waning of herd immunity because of lack of exposure making the population more susceptible.

The good news is that this year, the influenza AH1N1 component was updated to better reflect currently circulating viruses. The Center for Disease Control (CDC) preliminary figures from last season show 27 million to 54 million flu illnesses and 19,000 to 58,000 flu deaths, up from 8 million to 13 million flu illnesses and 5,000 to 14,000 flu deaths from last year. This increase is likely due to the loosening of public health precautions that were in place during the pandemic.

Who should receive each vaccine?
This year, the RSV immunization is especially promising for infants and adults 60 and over who are considered most at risk for severe outcomes. Last year, the common respiratory virus that usually causes mild, cold-like symptoms led to the hospitalization of 58,000 to 80,000 children under 5 and killed 100 to 300 children. It also accounted for 60,000 to 160,000 hospitalizations and 6,000 to 10,000 deaths among adults 65 years and older.

The CDC recommends that infants 8 months and younger during RSV season receive an RSV immunization. Older babies—in their second RSV season—may remain at high risk for complications from RSV infection and may require a second immunization. Adults 60 and older and people with heart and lung disease also should consider being vaccinated.

Everyone 6 months or older should receive the flu vaccine, especially if they are at higher risk for complications and mortality. Pregnant women should receive the flu shot to prevent severe symptoms and help confer some immunity to their newborns.

Similarly, everyone 6 months or older can receive an updated COVID-19 mRNA vaccine. This vaccine has been selected to better represent the COVID-19 variants that are currently causing infection.

When is the optimal time to get each vaccination?
The CDC recommends that people receive flu vaccinations by late October. The vaccine is effective for about six months so if you get vaccinated too early there is a chance your immunity might wane. Children receiving their first influenza vaccine need a second dose at least four weeks later. Check with your doctor.

COVID vaccines have become like flu vaccines, which are annually updated. This means we can expect updated COVID vaccines every year for protection against surges of the virus in the winter. This season’s vaccine targets the currently circulating XBB.1.5 Omicron subvariant.

Since RSV season starts in October, vulnerable people should receive the vaccine as soon as it’s available.

While the CDC says it is safe to get your flu shot and COVID vaccines simultaneously, the CDC has not yet issued a recommendation as to whether the RSV shot can be given simultaneously since there are few data on RSV to support recommending giving it on the same day.

How can I tell if I have the flu, coronavirus or RSV?
Flu symptoms can be confused with COVID. If you start feeling ill, it is important to quarantine and test for COVID to rule it out.

The symptoms for RSV are like the common cold. They tend to run their course with only mild intensity in adults and older children. In infants and the elderly, symptoms tend to be more severe and can include fevers and wheezing.

Are these vaccines safe?
Extremely rare side effects – like allergic reaction – can happen, but the risk is still lower than with many other common medications. You can get a flu shot even if you are allergic to eggs. Serious reactions to the small amount of egg protein in flu vaccines are unlikely.

Can you get the flu, COVID or RSV from the vaccine?
These vaccines take two weeks to be effective, so people still could contract these viruses during this period. COVID-19 vaccines contain no live virus so there is no way to become infected from the vaccine. With the flu vaccine, live viruses are grown but killed so there is no possibility of infection after vaccination either.