Immunity to the pandemic virus A (H1N1): Norway is probably well-prepared for major new outbreaks

Aug 24, 2010

By autumn 2009, almost half of the population of Norway had been vaccinated against the pandemic influenza A (H1N1) virus. Many had also been infected by the virus during the summer and autumn outbreaks. The majority of those who were vaccinated or were infected are expected to have developed immunity to the virus. A study of the Norwegian population's immune status to the pandemic virus in January 2010 was recently published in the journal Eurosurveillance.

For many years the Norwegian Institute of (NIPH) has monitored the population's immune status for by studying antibodies in blood samples. The annual collection usually takes place in August but an extra collection was made in January 2010 in connection with the pandemic to see what effect vaccination and infection had had on the population's immunity. Samples taken in 2008 were also studied to see how many people already had some form of immunity before the pandemic occurred.

The study found that at the beginning of 2010 nearly 60 percent of the population had measurable immunity to the pandemic virus, with 45 per cent having a sufficient immunity to protect against the disease.

"This is a substantial increase because few had antibodies against the new virus prior to the pandemic" said Olav Hungnes, a researcher at the Department of Virology at the NIPH.

"Even though many acquired immunity through infection, we believe that vaccination may have been responsible for most of the increase. The population of Norway is particularly well prepared for major new outbreaks of , compared with countries where fewer received the . Even those who are not immune will benefit from the fact that the spread of infection would be slowed by others' immunity - we call this herd immunity," said Hungnes.

The proportion of young people who developed immunity is high, probably because both the rate of vaccination and the extent of infection were high.

It remains to be seen how well immunity remains over time and the NIPH will continue to monitor the population's immunity.

Explore further: Tobacco use varies widely among Asian and Pacific Islanders in US

Provided by Norwegian Institute of Public Health

not rated yet
add to favorites email to friend print save as pdf

Related Stories

1918 and 2009 H1N1 flu probably not spread by birds

Jan 19, 2010

The two strains of the H1N1 influenza virus responsible for the 1918 and 2009 global flu pandemics do not cause disease in birds. The results of the study, published in the February issue of the Journal of General Virology, also s ...

Recovering antibodies from 1918 flu pandemic survivors

Nov 11, 2008

(PhysOrg.com) -- Ninety years after the sweeping destruction of the 1918 flu pandemic, researchers at the Monroe Carell Jr. Children's Hospital at Vanderbilt have recovered antibodies to the virus — from elderly survivors ...

Recommended for you

Autonomy and relationships among 'good life' goals

1 hour ago

Young adults with Down syndrome have a strong desire to be self-sufficient by living independently and having a job, according to a study into the meaning of wellbeing among young people affected by the disorder.

Obama: 8 million signed up for health care (Update)

16 hours ago

President Barack Obama said Thursday 8 million Americans have signed up for health care through new insurance exchanges, besting expectations and offering new hope to Democrats who are defending the law ahead ...

User comments : 0

More news stories

Vietnam battles fatal measles outbreak

Vietnam is scrambling to contain a deadly outbreak of measles that has killed more than 100 people, mostly young children, and infected thousands more this year, the government said Friday.