Hyderabad: Herd immunity or community immunity, also referred to as herd protection, describes a scenario where a large part of the population is immune to an infection which prevents it from spreading.

A Facebook post which shows a graph from Johns Hopkins University has claimed that the USA has reached herd immunity. The post has notched 3,600 shares

The graph is meant to indicate whether a community is doing enough testing or not. This week, a lengthy Facebook post with 1,55,000 views falsely claimed that a declining positivity rate for COVID-19 tests means the US has reached herd immunity, the point where there is a sufficiently high proportion of immune people in the population to stop the spread of the disease.

POSITIVITY RATE SHOWS HERD IMMUNTIY HAS BEEN REACHED.In fact, it was probably reached in May.In this graph from…

Posted by Matthew McBride, Health Policy Expert on Tuesday, August 4, 2020

Archived claim can be seen here.

The Facebook user, identifying himself as a ‘Health Policy Expert’ used the graph from Johns Hopkins University’s Coronavirus Resource Center to argue that a dip in positive cases as a percentage of total tests indicates the coronavirus is ‘petering out.’

“Ask any biostatistician what it means when you test hundreds of thousands of people a day for infectious disease and return a consistently lowering the positivity rate. I’ll give you a clue: it means heard (sic) immunity has been reached and the virus is dying out,” he said in a message enclosing the graph.

Fact Check:

The rate of positive COVID-19 tests in the United States does not indicate that herd immunity has been reached. So, the claim is FALSE.

According to the Associated Press, Dr. Jennifer Nuzzo, the lead epidemiologist on the team who made the graph at Johns Hopkins has said that’s not at all what it shows. People were misinterpreting the graph as showing how easily the virus is spreading.

“You can’t say this is a measure of the amount of infection that’s occurring in the community,” Nuzzo said.

The number of positive tests as a percentage of total tests provides insight into whether more testing is needed and which members of the population are being tested, according to Nuzzo’s team.

A high positivity rate suggests that a community might be testing mostly the sickest patients, and could be missing milder or asymptomatic cases. A lower positivity rate may indicate a community is also testing patients with milder or no symptoms.

Experts estimate that to achieve herd protection from the new coronavirus through infection, at least 70% of the population in the U.S. i.e. 200 million people would need to have recovered from the COVID-19 and develop antibodies against future infections.

Recent projections range around 50%.

Antibody immunity to COVID-19 may only last for a few months.

Hence, the claim is FALSE.

This fact check has been published as part of the Internews Information Saves Lives: Rapid Response Fund project to NewsMeter

Mounika Dasari

Mounika Dasari is currently working as a Freelance Fact checker at Newsmeter. She was also an independent contractor at Appen. She has previously worked with Manshuk Securities and Finance as a Derivative Trainee in Delhi. She has work experience of 18 months with Geojit Financial Services as an Equity Dealer in Hyderabad. She has certifications of NISM series V, NISM Series VII, and NISM Series VIII. Alumni from IILM Graduate School of Management in Finance, U.P. Alumni from FH-Dortmund University of applied science and arts in Managing Diverse Markets, Germany. Mounika loves to travel and has been to countries like Germany, Netherlands, Italy, and Switzerland.

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