When to Get a Flu Shot This Year, According to Doctors

Mid-September through October is the sweet spot for getting a flu vaccine, but it’s almost never too late to get your jab.

The previous flu season witnessed a remarkable reduction in cases in the United States, marking a historic low of slightly over 2000 cases, as per government data cited by JAMA. This decline can be attributed in part to the precautions taken during the COVID-19 pandemic. In the absence of a COVID vaccine, individuals diligently adopted preventive measures such as mask-wearing, hand hygiene, and social distancing. These strategies proved potent against various respiratory illnesses, encompassing not only COVID-19 but also influenza and the common cold.

Before the prominence of the COVID-19 pandemic, influenza stood as a formidable threat among respiratory diseases in the US. In the 2019-2020 flu season, immediately preceding the pandemic outbreak, an estimated 38 million Americans contracted influenza, resulting in a tragic death toll of 22,000, as reported by the US Centers for Disease Control and Prevention (CDC).

This leads us to the 2021-2022 flu season, which presents apprehensions of a potential resurgence in flu cases. With the resumption of in-person schooling, increased indoor gatherings at venues like bars, restaurants, theaters, and concert halls, and the upcoming holiday season, the risk of overwhelming the healthcare system with simultaneous COVID-19 and influenza cases looms—the dreaded “twindemic.”

Infectious disease authority Amesh A. Adalja, MD, a senior scholar at the Johns Hopkins Center for Health Security in Maryland, stressed the significance of mitigating the impact of the flu, given the shared strain on hospital resources, personal protective equipment, and diagnostic supplies with COVID-19.

Thankfully, there exists an effective preventive measure: receiving a flu vaccine. The CDC strongly advocates that all individuals aged six months and older should receive an annual flu shot, with a few exceptions, including those with compromised immune systems, individuals with severe allergic reactions to the vaccine or its components, and those who have experienced severe reactions to the vaccine in the past.

Dr. Adalja emphasized the importance of maximizing flu vaccine uptake, while also highlighting the optimal timing for its administration. To ensure comprehensive protection this season, it is vital to be well-informed about the ideal timing for obtaining the flu shot.

When should I get the flu shot?

If you’re perusing this during September or October, you’re on track: experts concur that this period is optimal for obtaining a flu shot, with the aim of being vaccinated before October concludes. This strategic timeline allows the body ample time to develop robust defenses against the influenza virus before the onset of the active flu season. Furthermore, this approach guarantees sustained protection during the peak flu season. According to epidemiologist Supriya Narasimhan, MD, head of the infectious disease department at Santa Clara Valley Medical Center in California, it typically takes about two weeks following vaccination for sufficient antibodies to generate and establish full immunity.

However, if you happen upon this information in November, December, or even January, there’s no need for concern, as indicated by the CDC. Although flu activity in the United States typically commences in October and reaches its zenith between December and February, it may persist until May on occasion. Therefore, even if October has elapsed, it’s crucial not to forgo the vaccine this year.

How soon is too soon to get a flu shot?

There’s a balance to strike when it comes to timing your flu vaccine. While you might notice your local pharmacy offering flu shots as early as late summer, it’s wise to resist the immediate urge to get one. Waiting until September or October ensures that you derive the maximum benefits from the flu vaccine precisely when you’re most likely to require its protection.

Guided by insights from the CDC and infectious diseases experts, the prevailing consensus suggests avoiding vaccinations earlier than September. This precaution is rooted in the understanding that immunity against the flu virus gradually diminishes over time. The prime effectiveness of the flu shot occurs within the initial three months post-vaccination, though individuals still maintain a protective shield for at least six months after receiving the shot.

The optimal window for vaccination—spanning mid-September to October—strategically ensures that the vaccine remains potent throughout the active flu season. This counsel holds particular significance for adults aged 65 and older, given that their vulnerability escalates if their protection weakens significantly before the conclusion of flu activity for the season.

When to get the flu vaccine if you’re pregnant

The optimal timing for receiving the flu vaccine remains consistent for everyone, including pregnant individuals. Contrary to any inclination to postpone until after the first trimester, the flu vaccine is safe and highly advisable throughout pregnancy. In fact, the significance of flu vaccines during pregnancy cannot be overstated.

According to William Schaffner, MD, medical director of the National Foundation for Infectious Diseases and professor of preventive medicine and infectious diseases at Vanderbilt University School of Medicine, pregnant women encountering the flu are more susceptible to severe disease and its complications. This vulnerability is rooted in the suppression of certain immune functions during pregnancy, potentially leading to heightened susceptibility to serious flu-related complications.

Dr. Schaffner expounds on another pivotal reason for pregnant women to prioritize flu vaccination: the transfer of influenza protection from mother to fetus via the placenta. This maternal immunity extends safeguarding to the newborn for the initial six months of life, a period prior to the child’s eligibility for their own flu vaccine.

A notable exception to the general flu vaccine timing guideline, as outlined by the CDC, applies to pregnant women in their third trimester. For these individuals, an early vaccination—ideally in July or August—ensures sufficient time to establish immunity before their babies are born.

However, while the flu vaccine is safe at any point during pregnancy, it’s vital to refrain from opting for the nasal spray version, as advised by Dr. Schaffner. Unlike injectable vaccines, the nasal spray employs a live attenuated virus that is rendered less potent, not inactivated. Although the nasal spray vaccine is incapable of causing the flu due to engineered properties that cause the virus to die post-inhalation, its side effects—such as nasal congestion, fever, and body aches—can sometimes mimic flu symptoms, as cautioned by the CDC.

Should I wait to get a flu shot if I’m getting a COVID vaccine or booster?

There’s no need for a dilemma here. It’s not only recommended but entirely feasible to receive vaccinations against both COVID-19 and influenza and if you prefer, you can even have these shots administered on the same day.

Initially, when the COVID-19 vaccines were introduced, individuals were advised to avoid any other vaccinations for a minimum of two weeks post-COVID vaccination. This cautious approach was taken to closely monitor potential side effects arising from the novel COVID shots.

However, the COVID-19 vaccines have demonstrated an exceptional safety record, prompting experts to now endorse the simultaneous or near-simultaneous administration of various vaccines. In an interesting development, major pharmaceutical companies such as Novavax and Moderna announced in September that they were actively developing combined booster shots addressing both COVID-19 and influenza. Regrettably, these innovative combinations won’t be accessible in time for the current flu season.

Experts stress that if you decide to receive both the COVID-19 and flu vaccines on the same day, it’s advisable not to have them administered in the same arm. This precaution serves to minimize the potential discomfort at the injection site.

Ultimately, the choice to secure protection against both COVID-19 and influenza through vaccination is a prudent and viable step toward safeguarding your health.

Morning, noon, or night: What’s the best time of day to get a flu shot?

Research from the University of Birmingham in England has suggested a potential advantage to receiving the flu vaccine in the morning. This study, published in 2016 in the journal Vaccine, focused on adults aged over 65. It revealed a subtle enhancement in immune response when the flu vaccine was administered before noon, as opposed to the afternoon. However, this advantage was modest and applied solely to two of the three strains present in that particular year’s vaccine—bearing in mind that flu strains evolve annually.

While the study implies a potential benefit to receiving the vaccine earlier in the day, medical professionals emphasize that the paramount concern is obtaining the vaccine in a timely manner to ensure protection throughout the current flu season. If you’re not inclined towards mornings, receiving the vaccine during the afternoon is a reasonable alternative. The pivotal point remains: make sure you receive the vaccine, whether through a shot or spray, at a time that aligns with your convenience.

As Dr. Narasimhan highlights, forecasting the nature of the upcoming flu season poses challenges, particularly with the resurgence of in-person learning in educational institutions. However, a constant remains: vaccinations against seasonal influenza and COVID-19 play a decisive role in averting sick days, hospitalizations, and fatalities associated with both influenza and COVID-19.