Friday December 13, 2019

U.S. Measles Outbreak Raises Concerns About Immunity in Adults

This has occurred even in adults with two documented doses of the vaccine, said Dr. Michael Phillips, chief epidemiologist at NYU Langone Health, which serves parts of New York City, a hot spot in the U.S. outbreak.

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People vaccinated in the United States since 1989 would most likely have received two doses of the combined measles, mumps and rubella (MMR) shot under federal guidelines, and that is still considered the standard for protection. Pixabay

Adults in the United States who were vaccinated against measles decades ago may need a new dose depending on when they received the shot and their exposure risk, according to public health experts battling the nation’s largest outbreak since the virus was deemed eliminated in 2000.

Up to 10 percent of the 695 confirmed measles cases in the current outbreak occurred in people who received one or two doses of the vaccine, according to the U.S. Centers for Disease Control and Prevention.

The figure illustrates what can happen when a large number of individuals, even those who have been vaccinated, are exposed to the measles. CDC recommends that people who are living in or traveling to outbreak areas should check their vaccination status and consider getting a new dose.

Dr. Allison Bartlett, an infectious disease expert at the University of Chicago Medicine, said the “continued vulnerability to infection” is why high-risk adults such as healthcare workers are routinely advised to get a second dose of the measles vaccine if they have not had one.

But knowing your vaccination status can be tricky, experts said.

“It’s complicated and often futile because it’s very difficult to resurrect those old records,” said Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center.

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Los Angeles County Department of Public Health experts, Muntu Davis, Health Officer, left, and Director Dr. Barbara Ferrer answer questions regarding the measles response and the quarantine orders during a news conference in Los Angeles Friday, April 26, 2019. VOA

People vaccinated in the United States since 1989 would most likely have received two doses of the combined measles, mumps and rubella (MMR) shot under federal guidelines, and that is still considered the standard for protection.

Anyone vaccinated between 1963 and 1989 would likely have received only one dose, with many people immunized in the earlier years receiving an inactivated version of the virus. Americans born before 1957 are considered immune as they would have been exposed to the virus directly in an outbreak.

Merck & Co Inc is the sole U.S. provider of the MMR vaccine. The company said in a statement that it has “taken steps to increase U.S. supply” of the vaccine due to the current outbreak.

HIGHLY CONTAGIOUS

The measles virus is highly contagious and can cause blindness, deafness, brain damage or death. It is currently spreading in outbreaks in many parts of the world.

According to the World Health Organization, 95 percent of a population needs to be vaccinated to provide “herd immunity,” a form of indirect protection that prevents infection in people too young or sick to be vaccinated. U.S. public health officials have blamed the current outbreak in part on rising rates of vaccine skepticism that have reduced measles immunity in certain communities.

For travelers to outbreak areas abroad, the CDC recommends adults consider getting another dose of MMR unless they have proof of receiving two prior doses, take a blood test showing immunity, or were born before 1957.

In general, the CDC says two doses of the measles vaccine should provide 97 percent protection; one dose should offer 93 percent protection. However, immunity can wane over time.

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Rapid blood tests are available that can detect whether a person is immune based on the level of measles antibodies, but the tests are not 100 percent reliable. Pixabay

This has occurred even in adults with two documented doses of the vaccine, said Dr. Michael Phillips, chief epidemiologist at NYU Langone Health, which serves parts of New York City, a hot spot in the U.S. outbreak.

He said in kids, “the vaccine is really effective,” but in some adults, memory T-cells, which recognize and attack germs, do not fight the virus as effectively as they once did.

Also Read: Acceptance Letters From Seven Prominent US-Based Universities, Indian Girl in Dubai Performing Her Best

Rapid blood tests are available that can detect whether a person is immune based on the level of measles antibodies, but the tests are not 100 percent reliable.

Adults who have any doubt about their immunity should get another dose, Schaffner said: “It’s safe. There’s no downside risk. Just roll up your sleeve.” (VOA)

Next Story

Vaccine Alliance GAVI to Invest $178 Million to Create Global Stockpile Ebola Vaccines

Vaccine group announce creation of ebola vaccine stockpile

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There are similar stockpiles for vaccines against yellow fever, meningitis and cholera. Pixabay

The vaccine alliance GAVI announced Thursday it would invest $178 million to create a global stockpile of about 500,000 Ebola vaccines, a decision that health officials say could help prevent future outbreaks from spiraling out of control.

The public-private partnership includes the World Health Organization, UNICEF, the Bill & Melinda Gates Foundation and the World Bank, among others. The funding announcement was made after a meeting of GAVI’s board. GAVI said the investment, which it called an estimate, will be provided between now and 2025.

Since the current outbreak in eastern Congo was identified last August, health officials have immunized more than 255,000 people with a recently licensed vaccine made by Merck. To date there have been nearly 3,200 confirmed Ebola cases, including more than 2,200 deaths, in what has become the second deadliest Ebola outbreak in history.

Dr. Ngozi Okonjo-Iweala, chair of Gavi’s board, called the creation of the Ebola vaccine stockpile a “historic milestone in humanity’s fight against this horrific disease.” GAVI said “a coordinating mechanism” to decide how and when vaccines will be used will be established with partner organizations.

There are similar stockpiles for vaccines against yellow fever, meningitis and cholera. Those limited shots are doled out to developing countries by WHO, UNICEF, the Red Cross and Doctors Without Borders after receiving technical advice from others.

Ebola Vaccine Stockpile
A healthcare worker from the World Health Organization prepares vaccines to give to front line aid workers, in Mbandaka, Congo. VOA

The Ebola vaccine stockpile will be available to all countries, but only developing countries will be able to get vaccines for free in addition to support for the logistical costs of mounting vaccination campaigns.

Jason Nickerson, a humanitarian affairs adviser at Doctors Without Borders, said the new stockpile would change how officials respond to future Ebola outbreaks.

“Knowing how many doses of the vaccine exist in the world, and then being able to get a supply of them to high-risk countries in a very quick way, gives us another tool to respond to these outbreaks,” he said.

Earlier this year, the medical charity publicly called for an independent committee to oversee Ebola vaccination efforts in Congo, saying WHO sometimes used arbitrary criteria to determine who would get immunized. It said the fact that Ebola was continuing to spread despite the large number of people vaccinated was a damning assessment of the response.

Containing this outbreak has been complicated by violence and misunderstandings in a part of Congo that had never reported an Ebola case before.

Also Read-Measles Kills 140,000 people, WHO Calls it “Collective Failure”

Last week, response activities were suspended after attacks killed four Ebola responders, including a member of a vaccination team. Multiple rebel groups operate in eastern Congo and the region has been described as a war zone.

WHO has warned continued attacks on health workers and Ebola clinics could undermine attempts to curb Ebola and prompt a resurgence of the disease. (VOA)