The Johnson & Johnson vaccine: The importance of clear messaging and numeracy

This article is originally published on the blog of Communiqué PR, EloQ’s fellow member in the Public Relations Network (PRN). With the on-going concerns in the early stage of COVID-19 vaccination in Vietnam, this article will address the usage of clear messaging and numerical data in communicating sensitive news.

The majority of my Communiqué PR teammates, along with their friends and families, have begun receiving their COVID-19 vaccines, including a significant number who just received shots from Johnson & Johnson (J&J).

So, when federal health authorities recommended pausing the use of the J&J vaccine to investigate potential rare, but dangerous, side effects of blood clots, there was significant discussion about it in our daily meeting on April 13.

That morning, several colleagues had woken up to text messages and phone calls from concerned family members, wanting to alert them of the news and encourage them to keep an eye out for symptoms.

To alleviate concerns, most of our colleagues reminded loved ones that only a tiny number of people who received the Johnson & Johnson vaccine experienced these rare but serious clots. They pointed out the Food and Drug Administration FDA and Center for Disease Control and Prevention (CDC) decided on the pause after just six people out of approximately 7 million experienced these side effects.

While this should be of tremendous comfort to people, it’s often hard to get our heads around numbers. As Dr. Ellen Peters, the Philip H. Knight chair and director of the Center for Science Communication Research (SCR) at the University of Oregon, points out in her book “Innumeracy in the Wild: Misunderstanding and Misusing Numbers,” a substantial percentage of the U.S. population struggles to understand or process data.

“The news doesn’t always present numbers in ways that people find as easy to grasp as stories about individuals,” said Dr. Peters. “When presenting numbers like the rare but serious clots possibly associated with the J&J vaccine, communicators should tell the public about the 6 people who experienced clots and also about the approximately 6,999,994 people who did not. Advising the public about the likelihood of other more common side effects, such as the appropriately 50% of people (about 3.5 million so far) who are likely to experience pain at the injection site, may also help by putting the rare side effect into perspective.”

Consider the language that acting chair of the FDA, Dr. Janet Woodcock, used in her introductory remarks at the April 14 press conference.

Dr. Woodcock said that “out of an abundance of caution, [the FDA and CDC are] recommending a pause in the use of the Johnson & Johnson COVID-19 vaccine due to reports of six cases of a rare and severe type of blood clot following vaccine administration.”

Then she spoke about wanting to understand events so they can provide information to health care providers and vaccine recipients. She stressed “these events appear to be extremely rare,” before bridging to the message that “COVID- 19 vaccine safety is a top priority for the federal government.” [1]

As we know, this had an immediate impact across our nation as pharmacies and health care providers canceled J&J vaccine appointments, or when possible, switched people to first doses of Pfizer or Moderna.

The longer-term implications of the pause remain to be seen. The J&J vaccine was a critical part of the Biden administration’s plans to get the country fully vaccinated.

On March 10, President Biden announced plans to buy an additional 100 million doses of the J&J vaccine.[2] The J&J vaccine is particularly important for reaching people in areas where there is limited refrigeration, which is required for both Pfizer and Moderna vaccines, or where it may be difficult for people to get two doses. If the pause is not lifted, it is unclear what will happen in these instances.

Then there are those who were already wary of the vaccine. According to a poll released on March 31 by KFF, “13% of respondents overall said they will ‘definitely not’ be vaccinated, signaling that significant hurdles remain in the nation’s vaccination campaign.”[3] The day before the halt of the J&J vaccine, two young women working at my local grocery store said they weren’t going to get vaccinated because of concerns.

Given all this, it’s essential that public health officials assure people that they’re being diligent with administering vaccines. They must also help people understand the much higher risk of contracting COVID-19, becoming seriously ill and dying from it, and how this compares to the risk of experiencing a rare side effect from the vaccine.

This is no small communication task. Public health officials will need to be deliberate in their messaging. They’ll need to carefully consider the examples and data they share.

While people’s abilities to process and use numbers vary, communicators should not shy away from sharing quantitative information. According to Peters, studies show that people prefer actual numbers as opposed to more qualitative verbal descriptions.

In her book, Peters shares the results from a study on breast cancer and mammography risk information. When people use qualitative labels such as “low chance” or “common” as substitutes for numbers, there are varying interpretations of what those labels mean. In these instances, actual numbers are better.

In the coming days and weeks, many of us will carefully monitor and assess the news closely for honest, transparent, clear and timely information from public health officials. Leveraging numerical data can help effectively convey the important messages they wish to send.

Read other articles and advices on communications:

[1] “FDA and CDC announce a pause in administering the Johnson ….” 13 Apr. 2021,

[2] “Biden announces plan to purchase additional 100 million ….” 10 Mar. 2021,

[3] “Covid Vaccine Hesitancy Drops Among All Americans, New ….” 30 Mar. 2021,

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