{"id":19183,"date":"2021-07-29T09:57:24","date_gmt":"2021-07-29T14:57:24","guid":{"rendered":"https:\/\/thepapergown.zocdoc.com\/?p=19183"},"modified":"2026-08-14T12:00:22","modified_gmt":"2026-08-14T17:00:22","slug":"what-to-know-about-covid-breakthrough-infections","status":"publish","type":"post","link":"https:\/\/www.zocdoc.com\/blog\/guides\/what-to-know-about-covid-breakthrough-infections\/","title":{"rendered":"The Basics of COVID Breakthrough Infections"},"content":{"rendered":"<p><i>The information included in this article was current as of publication, however, information changes rapidly regarding Covid-19 and may be out of date.\u00a0<\/i><\/p>\n<hr \/>\n<p><span style=\"font-weight: 400;\">Once Sharone Peikes, 46, got her COVID-19 vaccine in March<\/span><b>,<\/b><span style=\"font-weight: 400;\"> she felt more comfortable going to her office, eating out and seeing friends and family. Excited to travel again, she planned a summer birthday trip to Miami. Then, days after returning home to New York, she woke up with a fever and a sore throat. Test results showed she was positive for COVID-19.<\/span><b>\u00a0<\/b><\/p>\n<p><span style=\"font-weight: 400;\">Now, about a week later, her symptoms are improving, but her sense of taste is still off. \u201cI\u2019m not sure if I got COVID on the plane or someplace else,\u201d says Peikes. \u201cBut I wish I never took off my mask and I doubled up.&#8221;<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Some breakthrough infections, meaning those in fully vaccinated people, were always expected. But, according to <a href=\"https:\/\/www.washingtonpost.com\/health\/2021\/07\/29\/cdc-mask-guidance\/\">a new internal CDC report<\/a>, the hyper-transmissible Delta variant, currently responsible for the vast majority of new COVID cases, is more likely to cause breakthrough infections than other versions of the virus. <\/span><\/p>\n<p><span style=\"font-weight: 400;\">In the groundbreaking report, <a href=\"https:\/\/www.washingtonpost.com\/health\/2021\/07\/29\/cdc-mask-guidance\/\">circulated by news outlets on July 29th<\/a>, the CDC also concluded that those who are vaccinated can actually transmit the virus to others. This finding prompted the agency to <\/span><a href=\"https:\/\/www.cdc.gov\/coronavirus\/2019-ncov\/vaccines\/fully-vaccinated.html\">revise its face-mask guidance earlier this week<\/a>, recommending that fully vaccinated people wear masks indoors in areas with \u201csubstantial\u201d or \u201chigh&#8221; transmission.<\/p>\n<p><span style=\"font-weight: 400;\">&#8220;You have to adapt to what the enemy is doing, and the enemy, in this case COVID-19, has thrown us a curveball,&#8221; says Dr. William Schaffner, a professor of preventive medicine at the Vanderbilt University Medical Center. &#8220;That curveball is Delta. We didn\u2019t know that in the summer. Now that Delta is among us, not changing [guidance] would be silly.&#8221;\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">While experts say there&#8217;s no need to panic about breakthrough cases, it&#8217;s worth<\/span><span style=\"font-weight: 400;\">\u00a0understanding the basics of these post-vaccination infections, and what to do if you suspect you have one.<\/span><\/p>\n<h3>How well do COVID vaccines protect against the Delta variant?<\/h3>\n<p>The vaccines appear to offer less protection against asymptomatic and minor infections from the Delta variant than other strains of the virus. But if you&#8217;re vaccinated, getting very sick from COVID remains unlikely.<\/p>\n<p>\u201cIf you have a breakthrough case, your risk of progressing to severe disease or even death is very low,\u201d <span style=\"font-weight: 400;\">says Dr. Ed Septimus, an infectious disease specialist and professor of medicine at Texas A&amp;M<\/span>. \u201cThe vaccine is doing what it\u2019s supposed to do.\u201d<\/p>\n<p>In <a href=\"https:\/\/www.thelancet.com\/pdfs\/journals\/lancet\/PIIS0140-6736(21)00947-8.pdf\">a study from Israel<\/a>\u00a0released earlier this month,\u00a0researchers\u00a0found the Pfizer vaccine to be 91 percent effective against severe COVID infections from the more contagious Delta variant, but only 39 percent effective overall and 41 percent effective against symptomatic infections.<span style=\"color: #000000;\"> The study was based on cases reported between June 20 and July 17.\u00a0<\/span>A UK study painted a more optimistic picture, finding two doses of Pfizer to be <a href=\"https:\/\/www.nejm.org\/doi\/full\/10.1056\/NEJMoa2108891?query=featured_home\">at least 88 percent effective against symptomatic <\/a><a href=\"https:\/\/www.nejm.org\/doi\/full\/10.1056\/NEJMoa2108891?query=featured_home\">D<\/a><a href=\"https:\/\/www.nejm.org\/doi\/full\/10.1056\/NEJMoa2108891?query=featured_home\">elta infections<\/a>.<\/p>\n<p>&#8220;All this boils down to two things,&#8221; says Schaffner. &#8220;If you\u2019re unvaccinated, get vaccinated, please. If you\u2019re vaccinated already, and you go indoors to a group event, wear a mask.&#8221;<\/p>\n<h3>If you\u2019re fully vaccinated, when should you get tested for a COVID breakthrough infection?<\/h3>\n<p><span style=\"font-weight: 400;\">For starters, it&#8217;s important to understand what \u201cfully vaccinated\u201d means, says Dr. Amy Mullins, director for quality and science at the American Academy for Family Physicians. It takes two weeks for currently available COVID vaccines to take full effect. (For two-dose vaccines, like Pfizer and Moderna, that means two weeks after the <\/span><i><span style=\"font-weight: 400;\">second<\/span><\/i><span style=\"font-weight: 400;\"> shot.) Until that period is up, you&#8217;re vulnerable to contracting a more serious case of COVID.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Most people test positive for COVID around five days after exposure, Septimus says. If you\u2019ve knowingly been exposed to COVID-19, you should <\/span><a href=\"https:\/\/www.cdc.gov\/coronavirus\/2019-ncov\/vaccines\/fully-vaccinated.html\"><span style=\"font-weight: 400;\">get tested anywhere from three to five days later,<\/span><\/a><span style=\"font-weight: 400;\"> whether or not you have symptoms, according to the CDC. Septimus recommends getting <\/span><a href=\"https:\/\/www.memorialhealthcare.org\/whats-the-difference-between-covid-19-rapid-and-prc-tests\/\"><span style=\"font-weight: 400;\">a PCR test<\/span><\/a><span style=\"font-weight: 400;\">, because it\u2019s the most reliable type.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">If you develop cold or flu-like symptoms, you should get a COVID test no matter what. Now that people are out and about in the world again, the minor respiratory viruses that died down during quarantine are circulating again. You may very well feel under the weather from a cold, not COVID. But it\u2019s worth knowing. \u201cIt\u2019s important to figure out what your illness is for both yourself and to protect others,\u201d he says.\u00a0<\/span><\/p>\n<h3>Why get tested for a breakthrough infection?<\/h3>\n<p><span style=\"font-weight: 400;\">Even if you don\u2019t have any symptoms, it\u2019s important to get tested if you\u2019ve been exposed to COVID so you don&#8217;t spread it.\u00a0<\/span><\/p>\n<h3>Should you assume you\u2019ve contracted a certain variant? Does it matter?<\/h3>\n<p><a href=\"https:\/\/www.cdc.gov\/coronavirus\/2019-ncov\/covid-data\/covidview\/index.html\"><span style=\"font-weight: 400;\">More than 80 percent of new COVID-19 cases in the US<\/span><\/a><span style=\"font-weight: 400;\"> are linked to the Delta variant, so it&#8217;s more likely than not that a breakthrough infection is Delta. Knowing the variant can be useful epidemiologically, says Septimus, but it shouldn&#8217;t affect how long you isolate or monitor your symptoms. Also, identifying the variant could help inform treatment if you need medical attention for a breakthrough infection. But determining whether or not you have the Delta variant requires additional screening, which is only available at some testing facilities.\u00a0<\/span><\/p>\n<h3>If you test positive, what&#8217;s the next step?<\/h3>\n<p><span style=\"font-weight: 400;\">First, put on a mask if you haven\u2019t already, especially if you\u2019re around unvaccinated people, including young children. Then, \u201cstay home so you don\u2019t expose anyone else,\u201d Septimus says.<\/span> <a href=\"https:\/\/www.cdc.gov\/coronavirus\/2019-ncov\/vaccines\/fully-vaccinated.html\"><span style=\"font-weight: 400;\">If your result is positive, <\/span><span style=\"font-weight: 400;\">CDC guidance is to isolate for 10 days<\/span><\/a><span style=\"font-weight: 400;\"> and wear a mask indoors in public for 14 days after exposure or until you get a negative test result. \u201cWe assume the amount of virus in people who are fully immunized is relatively low,\u201d Septimus says. \u201cThe question is, is it high enough to cause transmission to others? We have to take the right precautions until we know for sure.\u201d<\/span><\/p>\n<h3>Do breakthrough infections have the same symptoms as cases in unvaccinated people?<\/h3>\n<p>&#8220;It&#8217;s unusual for the vaccinated population to be sick enough to go to the hospital,&#8221; Schaffner says, even with the Delta variant.<\/p>\n<p><span style=\"font-weight: 400;\">Breakthrough infections are generally less intense; they&#8217;re likely to resemble a cold or a mild case of the flu. They might include some aches, a runny nose, sneezing, a sore throat, and vomiting, nausea or diarrhea. \u201cFor most breakthrough cases, we can treat at home, and people are getting better much faster without any medical intervention,\u201d Mullins says. For more serious issues like shortness of breath or chest pain, get medical attention right away.<\/span><\/p>\n<h3>Which groups are considered high risk for breakthrough infections?<\/h3>\n<p><span style=\"font-weight: 400;\">People with weakened immune systems, such as organ transplant patients, don\u2019t mount as strong a response to vaccination, so they might have an increased risk of breakthrough infections, and possibly more severe ones. Other potentially high-risk groups include people with autoimmune conditions who take immunosuppressant drugs, adults over age 65, and anyone with diabetes or obesity.<\/span><\/p>\n<h3>How can a breakthrough infection impact your immunity to COVID? Will it make you less susceptible to future variants?<\/h3>\n<p><span style=\"font-weight: 400;\">Not necessarily. Scientists still don\u2019t know for sure, and more research is needed. \u201cBut having a breakthrough infection probably boosts your immunity against COVID in general,\u201d Septimus says.\u00a0<\/span><\/p>\n<h3>People with \u201clong COVID\u201d report residual symptoms that persist for weeks or months. Could this happen from a breakthrough infection?<\/h3>\n<p><span style=\"font-weight: 400;\">\u201cWe don\u2019t think so,\u201d says Septimus, \u201cbut we don\u2019t know for sure.\u201d This is another area in need of additional research, so stay tuned.<\/span><\/p>\n<hr \/>\n<h1><style id=\"zia-frontend-inline\">.zia-ad {\n    --zia-radius: 24px;\n    --zia-band-pad: clamp(24px, 3cqw, 40px);\n    --zia-band-overlap: 24px;\n    display: block;\n    text-decoration: none;\n    position: relative;\n    aspect-ratio: 4 \/ 1;\n    container-type: inline-size;\n    box-sizing: border-box;\n    border-radius: 0;\n    margin: 0 0 24px;\n    font-family: \"Google Sans\", \"Product Sans\", -apple-system, BlinkMacSystemFont, \"Segoe UI\", Roboto, Helvetica, Arial, sans-serif;\n    background-repeat: no-repeat;\n    background-size: cover;\n    background-position: center;\n    background-image: var(--zia-bg-desktop, none);\n    transition: box-shadow 0.12s 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