doses are available. the prime minister insisted that at least 10,000 people are to be vaccinated per day. borisov's decision was viewed as in practice resulting in the abandonment of the phased approach to vaccinations. the u-turn in the government's policies has been attributed to the need to expedite the vaccination process and the vaccine reservations displayed by members of priority groups such as medical practitioners and educators, with only 24% of the latter expressing a wish to be vaccinated. the changed approach sped up the tempo of the vaccinations, with more than 30,000 doses administered in the first three days since the opening of the "green corridors". however, while medical practitioners carried on with the vaccinations, even if at a reduced pace, in a number of smaller cities, between 25 and 28 february the "green corridors" were temporarily discontinued in sofia and other large cities because of the country mostly running out of astrazeneca vaccines, with the remaining pfizer-biontech and moderna ones set aside for priority groups. after the arrival and distribution of 52,800 oxford-astrazeneca doses, the vaccinations involving non-priority targets resumed on 28 february. in contrast to the previous days, they saw a significantly more active role of the general practitioners than of the health inspectorates and the large hospitals, proceeding only if there are no people from phases 1-4 willing to be vaccinated. a long-distance view of a mobile vaccination point against covid-19 in the borisova gradina in sofia. on 8 march 2021, the health ministry took the decision to distribute a larger quantity of vaccines for the provinces where the infection rate is higher, such as kyustendil. on 11 march 2021, the people who had registered via the electronic system for vaccinations began receiving their injections, with all of them covered by either a pfizer-biontech or a moderna vaccine between 12 and 18 march due to a safety concern pertaining to astrazeneca. however, the booking of slots via the electronic registration system was put on hold, as the bulk of the vaccinations were to be with astrazeneca. vaccinations with the adenovirus vector vaccine resumed on 19 march, with the electronic registration option for new users restored on 20 march. during the month of march a significant number of physicians and teachers (falling within the first two phases of the vaccination plan) who had initially not made use of their priority status expressed a wish to be vaccinated. the month of april saw a much reduced interest in the astrazeneca vaccine among the members of the general public, with a strong preference for the rna vaccines. as a result of the plummeting popularity of astrazeneca, described as sinking to "symbolic percentages" by the health minister, kostadin angelov stated on 12 april 2021 that bulgaria will withdraw the vaccine from the vaccination programme if the enthusiasm for it reaches rock bottom. on 6 april 2021, general practitioners began receiving flasks of rna vaccines for their patients, though the quantities were limited. on 15 april 2021, the first doses of janssen, numbering 14,400, were delivered to bulgaria, but they remained in storage, as the national vaccination operational headquarters in bulgaria had not yet made a decision as to their use after the u.s. centers for disease control and prevention (cdc) and food and drug administration (fda) had earlier begun investigations of very rare cases of cerebral venous sinus thrombosis associated with this vaccine, with ema also reviewing the matter. on 26 april 2021, chief health inspector angel kunchev confirmed that bulgaria will give the green light to the johnson & johnson vaccine and it may be especially useful for vaccinating certain groups, such as those employed within the tourism sector as well as demographics that are less easily reachable like the romani people. vaccinations with this one-dose vaccine officially began on 28 april 2021, even though a limited number of doses of johnson & johnson had already been administered to selected target groups in the preceding days. "green corridors", mainly with rna vaccines, were opened up on 30 april, to be in operation until 9 may 2021. over 125,000 people managed to make use of them during these 10 days. on 10 may, it was confirmed that they would be extended, as there was a sufficient quantity of vaccines (more than 270 000 doses of pfizer vaccines had arrived on that date). on the same day, people who had specifically indicated a preference for rna vaccines from the electronic system began receiving them. johnson & johnson was initially not be offered as part of the "green corridors", but it eventually started to be administered in that fashion as well. a closer view of a mobile vaccination point against covid-19 in the borisova gradina in sofia. the fifth phase of the vaccination plan began in may 2021. on 8 may 2021, approximately 38,000 people were vaccinated, the highest number in a single day. the milestone of 1 million administered doses of vaccines had been reached by 12 may 2021, with 362,322 people fully immunized. on 17 may 2021, caretaker health minister stoycho katsarov who has been sharply critical of his predecessor due to the non-inclusion of elderly people in the first phase of the vaccination plan, issued a decree stipulating that only people over the age of 60 and/or those with chronic conditions are to receive injections at the different vaccination points from monday to thursday. following strong disapproval from kostadin angelov and public figures such as crisis management expert petar velkov, who viewed this measure as pointless due to enough vaccines being available for everyone, and entailing a risk of further slowing down of the general vaccination process, katsarov amended the decree on the next day, stating that while vulnerable people will still be prioritized, those under 60 and/or without chronic illnesses will not to be turned away if they decide to make use of a "green corridor" on one of the first four days of the week. as of 25 may 2021, 2.8 million vaccine doses had been delivered to bulgaria, of which under 1.3 million had been administered, while the amount of vaccines received by the country exceeded 3.5 million by the end of the month, with pfizer-biontech constituting the bulk of them. may 2021 was also the first month during which the number of injected first doses of vaccines was lower than in the preceding one. in june 2021, the ministry of health gave the green light for the vaccination of children aged 12 and over with the pfizer-biontech vaccine. on 12 june 2021, the caretaker health minister himself was himself immunized with a janssen covid-19 vaccine. as of mid june 2021, 36 children between the ages of 12 and 15 had been vaccinated, with few parents expressing an interest. the summer months saw a seriously dwindling interest in the vaccinations, though there was a small uptick in august. by 25 august 2021, 7130 school pupils over the age of 12 had been fully vaccinated while 11,688 had received one dose, with close to 10,000 expected to have completed their vaccination courses by 15 september. on 23 september 2021, the expert group of the ministry of health recommended a third vaccine dose, using pfizer–biontech, for people who are immunocompromised, are living in care homes, are health care workers, are aged over 65 as well as those satisfying other health-related criteria, including low virus-specific antibodies or immune cells, to be administered six to eight months after a completed vaccination course, with the possibility of this happening as soon as one month after a completed vaccination cycle in case the immunity generated is not sufficient. on 24 september 2021, ventsislav mutafchiyski and 11 other physicians from the military medical academy received a third shot from the vaccine. on 30 september 2021, the ministry of health clarified that all bulgarians, including those who do not fall within the five priority groups, are eligible for the booster dose, as long as sufficient time has passed since the completion of their original vaccination course. 890 third doses had been administered up to that date. on 19 october 2021, the health minister announced that from 21 october a "green certificate", entailing proof of vaccination, recovery from an infection or a negative covid-19 test will be required for all public activities taking place indoors. the announcement resulted in a significant increase in the number of people interested in getting a vaccine, many opting for the one-shot janssen. on 21 october, it was clarified that a temporary green certificate will also be issued to people who have had one injection in the case of a two-dose regimen. since 11 november 2021, green certificates valid for three months can also be issued to people following a quantity anti sars-cov-2 igg test, showing values exceeding 150 bau/ml. close to 360,000 vaccine doses were administered in the first three weeks since the announcement regarding the "green certificate" requirement, with a rising vaccine uptake among educators and school pupils. as of 18 november 2021, 28,331 doses had been administered to children aged from 12 to 17, with 12,136 with a completed vaccination course and 16,195 with one injection. on 20 december 2021, the first pediatric doses (for children between the ages of 5 and 11 years) of the pfizer-biontech vaccines arrived in bulgaria. the vaccinations in this age group began on 21 december in veliko tarnovo before commencing on the next day in sofia and other cities. on 30 december 2021, the health authorities announced that the time interval for the administering of a booster dose will be shortened to three months for the people with a two-dose vaccine regimen while those with the one-shot janssen vaccine will be able to receive it two months after the first injection. this new regulation does not apply to children. this decision has been attributed to the vaccine evading properties of the omicron variant whose presence was already suspected in bulgaria at the time. january 2022 saw a notable rise in the number of people visiting the vaccination centers, though a significant proportion of them were there for receiving their booster doses and there was a reversal of this trend during the second half of the month and in february 2022. by early february 2022, 2 million citizens had been fully vaccinated. as of 12 february 2022, the capital city of sofia had the highest vaccination coverage, with 41.93% of the people fully vaccinated while montana province had the lowest at 19.29%. starting from 24 february 2022, the rules for the green certificate began to be relaxed, with public establishments allowed to decide on their own accord whether to demand such a pass for their visitors, with the requirement remaining in place for employees and staff. the regulations pertaining to green passes for patrons of "establishments of societal importance" were further loosened from 10 march. as of 1 march 2022, more than 80% of physicians had been fully vaccinated, the highest of any occupation. on 17 march 2022, the ministry of health announced that from 21 march the green pass will no longer be required for any activities. on 1 april 2022, the council of ministers lifted the emergency epidemiological situation, approximately two years after it was introduced. the decision was met with skepticism by some experts due to the still low vaccination rate in the country. in april 2022, it was confirmed by the authorities that ukrainian citizens who have received temporary protection in bulgaria will be eligible to be vaccinated for free. as of 6 april 2022, 5,779,500 pfizer-biontech, 958,100 moderna, 4,518,400 astrazeneca and 1,777,300 janssen doses had been delivered to bulgaria. on 24 june 2022, the ministry of health approved the proposals of the expert council on the overview of immunoprophylaxis, allowing a second booster (with one of the two rna vaccines) for all people aged 18 and over. the second booster dose may be administered at least four months after the first one in the case of people whose completed vaccination cycle involving a two-dose regimen and is strongly advised for those belonging to high risk groups. on 27 june 2022, when the decision entered into force, 204 people received second booster doses. as of 1 september 2022, 53,401 vaccine doses had been administered in the 12-17 age group and 4498 in the 5 to