You should get your second shot as close to the recommended 3-week or 4-week interval as possible. However, your second dose may be given up to 6 weeks (42 days) after the first dose, if necessary. You should not get the second dose early.

If the live vaccine is given first, it is necessary to wait at least 2 weeks (i.e., an incubation period) before giving the antibody. If the interval between the vaccine and antibody is less than 2 weeks, the recipient should be tested for immunity or the vaccine dose should be repeated.

Children younger than 6 months old have the highest risk for being hospitalized from flu compared to children of other ages, but are too young to get a flu vaccine. Because flu vaccines are not approved for use in children younger than 6 months old, protecting them from flu is especially important.

The effects of the vaccine generally only last through one flu season, which is about six months long. That’s part of the reason you need one every year. Starting two weeks after you get a flu shot, you should be protected from certain influenza viruses for the remainder of that flu season.

If you have had 2009 H1N1 flu, as confirmed by an RT-PCR test, you should have some immunity against 2009 H1N1 flu and can choose not to get the 2009 H1N1 vaccine. However, vaccination of a person with some existing immunity to the 2009 H1N1 virus will not be harmful.

Is it possible to catch A(H1N1) twice? Yes, because the virus can mutate (change). If you become infected with the swine flu virus, your body produces antibodies against it, which will recognize and fight off the virus if the body ever meets it again.

Here’s what new research reveals. Survivors of Covid-19 are significantly less likely than the rest of the population to catch the novel coronavirus—but their risk of reinfection is not zero, according to a study published Wednesday in JAMA Internal Medicine.

How long is someone with H1N1 flu infectious to others? People with H1N1 flu virus infection should be considered potentially contagious one day before the onset of symptoms and as long as they are symptomatic, and possibly up to 7 days following the onset of illness.

From April 12, 2009 to April 10, 2010, CDC estimated there were 60.8 million cases (range: 43.3-89.3 million), 274,304 hospitalizations (range: 195,086-402,719), and 12,469 deaths (range: 8868-18,306) in the United States due to the (H1N1)pdm09 virus.

Intriguingly, rather than adapting to humans over time, it seems that H1N1 – the type that caused the 1918 flu pandemic and swine flu, and has now disappeared – had been quietly accumulating mutations which were useless or even actively harmful to its own survival.

These measures also help prevent the flu and limit its spread:

1. Wash your hands thoroughly and frequently. Use soap and water, or if they’re unavailable, use an alcohol-based hand sanitizer.
2. Cover your coughs and sneezes.
3. Avoid touching your face.
4. Clean surfaces.
5. Avoid contact.

Influenza A (H1N1) 2009 Monovalent Vaccine is an inactivated influenza virus vaccine indicated for immunization of persons 4 years of age and older against influenza disease caused by pandemic (H1N1) 2009 virus.

The 2009 flu pandemic vaccines were influenza vaccines developed to protect against the pandemic H1N1/09 virus. These vaccines either contained inactivated (killed) influenza virus, or weakened live virus that could not cause influenza. The killed vaccine was injected, while the live vaccine was given as a nasal spray.

What about a SARS vaccine? Vaccine studies for SARS-CoV-1 were started and tested in animal models. An inactivated whole virus was used in ferrets, nonhuman primates and mice. All of the vaccines resulted in protective immunity, but there were complications; the vaccines resulted in an immune disease in animals.

Common side effects of Influenza A (H1N1) 2009 Monovalent Vaccine Live, Intranasal include:

• wheezing.
• hypersensitivity reactions.
• runny or stuffy nose.
• decreased appetite.
• irritability.
• lethargy.
• sore throat.
• headache.

When there has been an increased risk, it has consistently been in the range of 1-2 additional GBS cases per million flu vaccine doses administered. Studies suggest that it is more likely that a person will get GBS after getting the flu than after vaccination.

Although related to the severe acute respiratory syndrome (SARS) and the Middle East respiratory syndrome (MERS), COVID-19 shows some peculiar pathogenetic, epidemiological and clinical features which to date are not completely understood.

The same flu vaccine that protects against seasonal flu also protects against the H1N1 swine flu strain. You can get it as a shot or as a nasal spray. Either way, it “teaches” your immune system to attack the real virus.

Scientists around the world have developed treatments and vaccines for the new coronavirus disease known as COVID-19. Several companies are working on antiviral drugs, some of which are already in use against other illnesses, to treat people who have COVID-19.