BRASILIA/RIO DE JANEIRO, June 19 (Reuters) - Thousands took to the streets across Brazil on Saturday to protest against President Jair Bolsonaro"s pandemic response, blasting the leader for not acquiring vaccines fast enough and for questioning the need for mask-wearing. Brazil surpassed 500,000 deaths from COVID-19 on Saturday, according to the Health Ministry, the world"s highest death toll after the United States.[nL2N2O10FX] The government faces fierce criticism for passing up early opportunities to buy vaccines. Pharmaceutical maker Pfizer said it got no response to offers to sell vaccines to the government between August and November last year. read more "We are protesting against the genocidal Bolsonaro government that did not buy vaccines and has done nothing to take care of its people in the last year," said 36-year-old Aline Rabelo, while protesting on the national mall in Brasilia. Bolsonaro"s press office did not respond to request for comment. Only 11% of Brazilians are fully vaccinated and 29% have received a first dose, Health Ministry data shows. Brazilian media reported that protests had been held in all 26 states as well as the capital Brasilia. Many demonstrators called the 500,000 dead a form of genocide carried out by the government on the Brazilian people. They chanted, beat drums and held up signs demanding Bolsonaro be removed for office. "Half a million reasons to oust Bolsonaro," read one protestor"s sign in downtown Sao Paulo. While organizers promised the largest demonstrations yet in more than 300 cities, gatherings in Rio de Janeiro and Brasilia on Saturday morning did not appear to be larger than the last major protests on May 29. Protests in Sao Paulo, Brazil"s largest city and financial center, blocked major downtown thoroughfares, where protesters unfurled a banner the size of a city block demanding "Life, Bread, Vaccines and Education." It was unclear how the crowd compared to May 29 protest there. A special Senate committee is probing the Bolsonaro administration"s pandemic response, highlighting delayed efforts to acquire vaccines while prioritizing unproven treatments for COVID-19. Last month, a poll showed Bolsonaro"s popularity has sunk to new lows with only 24% of Brazilians saying his administration is "good" or "great." The same poll showed Bolsonaro"s left wing rival, former President Luiz Inacio Lula da Silva, would win in a run-off vote if the 2022 elections were held today. read more