Allissa Sanchez, LVN, gives her patient a vaccine during a flu and COVID-19 vaccination clinic at Kaiser Permanente Pasadena on Thursday, Oct. 12, 2023, in Pasadena, CA.
CNN  — 

Now is the time to get vaccinated to stay safe and healthy amid holiday gatherings and rising levels of respiratory viruses, including the flu, Covid-19 and RSV, experts say.

“To protect yourself and your family this holiday season, take the steps that we do every year to protect ourselves,” Dr. Mandy Cohen, director of the US Center for Disease Control and Prevention, said in a video posted to social media Wednesday. “It’s not too late to get vaccinated if you haven’t already.”

It takes about two weeks for vaccines to provide optimal protection, so getting the shot now would lead right into Christmas. But the shots offer some additional protection before that, and well after.

“Do it right away,” said Dr. William Schaffner, an infectious disease expert at Vanderbilt University. “The bulk of the winter is yet to come, so still protect yourself.”

So far this season, vaccination rates are low – but respiratory virus transmission is high.

Weekly hospitalizations for flu, Covid-19 and RSV are on the rise, CDC data shows. During the week ending November 18, there were about 7 new respiratory virus admissions for every 100,000 people, about 35% higher than a month earlier.

Covid-19 levels in wastewater, a leading gauge of viral transmission, are high and rising, while flu is increasing across most of the US and RSV levels are elevated, according to the CDC. And overall, outpatient visits for flu-like illness – a fever, as well as a cough or sore throat – are well above baseline nationally. Levels are high in 15 states, especially across the South.

The CDC recommends an annual flu vaccine, as well as the updated Covid-19 shot, for everyone age 6 months and up. And there’s a new RSV vaccine this year, recommended for those 60 and older.

Yet fewer than 2 in 5 adults and children have gotten the flu vaccine this season, according to CDC estimates. About 16% of adults – and only 7% of kids – have gotten the latest Covid-19 vaccine, while about 15% of older adults have gotten the new RSV vaccine.

A KFF survey from November found that most adults in the US are not worried about getting sick with Covid-19 or spreading it over the holidays, but experts urge caution. And CDC forecasts suggest that this respiratory disease season will be similar to last year — which saw hospitals more full than at any other point in the pandemic — and worse than pre-pandemic years once again.

“We have an early signal that these viruses are not going to go away and will be active in our communities,” Schaffner said. “We can mitigate that – reduce that impact – if, as a population, we take advantage of these vaccines. And furthermore, we’ll also reduce some of the stress on our health care systems.”

It is safe to get a flu vaccine and a Covid-19 vaccine at the same visit, according to the CDC.

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This might be a more convenient option, especially for those who have delayed getting their shots. Vaccines given at the same visit should be given in different arms, or at least one inch apart, the CDC says. Beyond that, getting both shots at the same time does seem to make it a bit more likely that you’ll experience a temporary reaction to the shots; the most common symptoms reported in a government study were fatigue, headache and muscle pain.

In addition to vaccines, experts urge people to use additional layers of protection during respiratory virus season – especially those at higher risk of developing severe disease, including seniors, pregnant people and those with underlying or chronic medical conditions.

“Use additional layers of protection like avoiding people who are sick, washing your hands, improving ventilation and wearing a mask,” Cohen said. “And if you do get sick, I know it’s hard, but stay home so you don’t spread germs to others. And get tested so you know what you have and get treatment.”

CNN’s Brenda Goodman contributed to this report.