Adriane Casalotti is the chief of public and government affairs for the National Association of County and City Health Officials. She said that we now know more about Delta than we do about the past. This will allow us to determine what mitigation strategies and rules we need in our community.On Tuesday, the CDC highlighted the importance of tracking. Director Rochelle Walensky stated that her agency had recommended that vaccinated persons wear masks indoors in certain areas. This was based on new data from a Massachusetts outbreak that showed that people who have been vaccinated can spread the Delta variant just as easily as those who are not. Although Covid-19 is less common in vaccinated persons, CDC says that they could play an unknowing part in causing or continuing outbreaks.The agency's decision to limit reporting on breakthrough cases has led to wide variations in the way states monitor them.According to a POLITICO survey, at least 30 states monitor all breakthrough infections. Eight other states, including South Carolina, Texas, and Ohio, said they are following the CDC's guidelines and only collecting data about severe cases. Iowa and Missouri were the only two states that they don't have data on breakthrough cases.This makes the situation even more complicated. Many fully vaccinated individuals have stopped seeking testing in recent months if they have been infected. There has been a decline in the number of tests that can be performed to identify variants. It takes weeks for the sequencing data from laboratories to reflect in CDC's estimates of the variant prevalence.When asked about their breakthrough policy, CDC stated that focusing on patients with severe diseases helps to maximize the quality data collection on cases of greatest clinical or public health importance.Walensky spoke out more strongly during Tuesday's press conference, saying that it was common for people to believe her agency is not doing enough to study the patterns of infection among vaccinated persons. She said that the CDC would soon release data about the thousands of people who have contracted Covid-19 in the United States.Focused studies are being conducted in many hospitals, academic medical centers and nursing homes across the country by the agency. The agency also publishes model estimates every 2 weeks about the prevalence of Covid-19 variants across different geographical regions. These are based on sequencing data from national testing laboratories.Critics argue that the CDC is slow to update variant data and the information isn't granular enough.Sen. Tammy Baldwin (D-Wis.), who pushed to include genomic sequencing funding in Biden's coronavirus relief package, stated that I don't believe twice a week is enough.Others, like Sen. Ed Markey (D.Mass. Others, such as Sen. Ed Markey (D-Mass.), have urged the agency to track breakthrough infections. They argue that the country should monitor all Covid-19 cases among vaccinated persons to determine vaccine effectiveness and aid local officials in mitigating or preventing new outbreaks.Rick Bright, senior vice president for pandemic response and prevention at the Rockefeller Foundation said that the U.S. should document a representative sample of breakthrough diseases. He suggested that the creation of a surveillance system to collect data from more people vaccinated against mild or asymptomatic infections could help public health officials better understand how these variants spread.Bright, who was the leader of the Biomedical Advanced research and Development Authority, stated that tracking a wide range of breakthrough viruses is essential to identify the next variants and mutations and then to get ahead of them. It is therefore extremely concerning that the CDC has chosen to concentrate on just a few of these viruses from vaccine breakthrough cases.A better reporting of all breakthrough infections, focusing on those who develop symptoms of Covid-19, could have helped CDC to issue its most recent guidance on mask-wearing in a clearer, easier-to-understand, and more widely accepted way. David Holtgrave, dean of School of Public Health at University at Albany, recently co-authored a JAMA op ed arguing in favor of increased surveillance of Covid-19 among vaccinated persons.It seems that the tide is turning. The CDC quietly changed its long-held belief that people who spend time with infected persons don't need to be tested unless they experience symptoms. The CDC now recommends testing after three to five working days. This could be helpful in identifying new variants among the vaccinated.Some state officials and experts argue that it is not necessary to monitor mild or asymptomatic breakthroughs. They claim that the focus of focused studies and information about hospitalizations can provide a better view of those most vulnerable to severe infections.Marcus Plescia (the chief medical officer of the Association of State and Territorial Health Officials) stated that it is useful to learn about breakthroughs that lead to severe illness and that breakthroughs that lead to self-limiting illness. But I don't know if we need CDC guidelines or every state collecting and reporting this data. This is being investigated in academic institutions.The fragmented US health care system can make it difficult to track breakthrough cases in states that do not have a unified immunization registry, hospitals, or labs. When responding to crises, both federal and state agencies have to make a choice between speed and care.It is possible to spend a lot of energy and effort on something that we know will happen, but with little consequence, stated Andy Slavitt during a recent media conference. The former official admitted that the U.S. would be better served if the system could quickly track and identify variants of concern.Jennifer Nuzzo, an epidemiologist at Johns Hopkins University's Bloomberg School of Public Health, said that the CDC used data this week to alter its testing guidance and masking. This raises new questions that can be best addressed through targeted epidemiological investigations rather than widespread surveillance of breakthrough patients.Nuzzo stated that it's not necessary to have a comprehensive surveillance effort in which all states must report cases to CDC. We should make an effort to find out how often they happen and what we should do about them.Officials from some states understand the reasons CDC focuses on cases of severe breakthroughs, but they believe a more complete national picture could prove beneficial.Jinlene Chan, Maryland's deputy secretary for public health services, stated that understanding the nature of any new variants, such as the Delta variant, or any future variants, helps us to determine the best approach, she said.